Diversification and the resource curse: An econometric analysis of GCC countries

Abdelkawy, Nagwa Amin Article Diversification and the resource curse: An econometric analysis of GCC countries Economies Provided in Cooperation with: MDPI – Multidisciplinary Digital Publishing Institute, Basel Suggested Citation: Abdelkawy, Nagwa Amin (2024) : Diversification and the resource curse: An econometric analysis of GCC countries, Economies, ISSN 2227-7099, MDPI, Basel, Vol. 12, Iss. 11, pp. 1-29, https://doi.org/10.3390/economies12110287 This Version is available at: https://hdl.handle.net/10419/329214 Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in EconStor may be saved and copied for your personal and scholarly purposes. You are not to copy documents for public or commercial purposes, to exhibit the documents publicly, to make them publicly available on the internet, or to distribute or otherwise use the documents in public. If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence. https://creativecommons.org/licenses/by/4.0/ Citation: Abdelkawy, Nagwa Amin. 2024. Diversification and the Resource Curse: An Econometric Analysis of GCC Countries. Economies 12: 287. https://doi.org/10.3390/ economies12110287 Academic Editor: George R. G. Clarke Received: 14 September 2024 Revised: 18 October 2024 Accepted: 23 October 2024 Published: 25 October 2024 Copyright: © 2024 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). economies Article Diversification and the Resource Curse: An Econometric Analysis of GCC Countries Nagwa Amin Abdelkawy Department of Economics, School of Business, King Faisal University, Al-Ahsa 31982, Saudi Arabia; [email protected] Abstract: This research explores the effects of significant global economic shocks, such as the 2008 Global Financial Crisis and the 2020 COVID-19 pandemic, on GDP growth in the Gulf Cooperation Council (GCC) nations. Employing a dynamic generalized method of moments (GMM) model, the analysis highlights the strong momentum effect of lagged GDP growth, where past performance plays a critical role in shaping current economic outcomes. The findings also reveal that natural resources continue to positively influence short-term growth, but with diminishing returns over time, supporting the resource curse hypothesis and underscoring the need for broader structural reforms to ensure long-term sustainability. In addition, the results show that external investments flowing into the country, trade balance, and inflation emerge as key drivers of economic growth. While moderate inflation is positively associated with economic expansion, unemployment exerts a significant negative effect on GDP growth, particularly in models that account for country-specific characteristics. This emphasizes the need for labor market reforms to improve employment rates and support sustainable development. The role of gross capital formation, particularly in both the dynamic GMM and random effects models, further underscores the importance of strategic domestic investment, especially during periods of global disruption. These findings emphasize the critical need for economic diversification in the GCC. Policymakers should focus on attracting foreign investment, managing inflation, enhancing human capital, and boosting domestic investment to mitigate the adverse effects of the resource curse and secure sustainability. While market capitalization and oil rents may stimulate short-term growth, their long-term sustainability remains uncertain without greater diversification. Both external and domestic investments emerge as critical drivers of longterm growth, while persistent challenges such as inflation and unemployment continue to pose risks to economic stability. The study highlights the need to reduce reliance on oil and leverage human capital to build more resilient economies capable of adapting to future challenges. By offering dynamic, empirical insights into the balance between resource reliance and sustainable growth, this research adds valuable insights to the policy discussion on economic diversification in the GCC. Policymakers are urged to prioritize FDI, inflation management, domestic capital formation, and human capital development to mitigate vulnerabilities and ensure sustainable economic growth in the face of ongoing global uncertainties. Keywords: economic resilience; diversification; resource dependency; GCC countries; financial markets; oil rents; dynamic panel data; sustainable growth 1. Introduction The Gulf Cooperation Council (GCC) countries, endowed with vast oil reserves, have long relied on these resources to fuel economic growth and improve living standards. However, this heavy dependence on oil revenues has made these economies particularly vulnerable to the volatility of global oil prices, underscoring the critical need for diversification to ensure sustainable, long-term growth. The GCC’s reliance on oil has been characterized by what is commonly referred to as the resource curse—a phenomenon where resource-rich countries often experience slower economic development, institutional Economies 2024,12, 287. https://doi.org/10.3390/economies12110287 https://www.mdpi.com/journal/economies Economies 2024,12, 287 2 of 29 weaknesses, and limited diversification due to the overwhelming focus on natural resource extraction. Despite numerous initiatives aimed at reducing their reliance on oil, the GCC countries still face significant challenges in achieving a more diversified and resilient economic structure. This study explores the complex nexus between market capitalization, oil dependency, and key socio-economic factors in the GCC countries from 2000 to 2022. Specifically, it aims to answer the following research question: How do market capitalization, oil rents, and socio-economic factors—including foreign direct investment (FDI) and gross capital formation (GCF)—interact to influence GDP growth in these oil-dependent economies? The study is driven by the following hypotheses: Hypothesis 1. Market capitalization initially drives economic growth but exhibits diminishing returns over time if not supported by broader structural reforms. Hypothesis 2. Oil rents, while contributing to short-term GDP growth, constrain long-term economic expansion, illustrating the effects of the resource curse. The resource curse theory posits that oil dependency leads to the underdevelopment of other sectors, limits innovation, and exacerbates economic volatility. Hypothesis 3. Foreign direct investment and gross capital formation, along with socio-economic factors such as human capital development, inflation, and unemployment, play pivotal roles in driving sustainable, long-term economic growth. To rigorously test these hypotheses, the study employs advanced econometric techniques, particularly the dynamic GMM model, which allows for a nuanced analysis of both the immediate and delayed effects of market cap, oil rents, both external and domestic investments, and socio-economic factors on GDP growth. This dynamic approach is particularly suited to capturing the evolving nature of economic growth in resource-dependent economies like those in the GCC. It also provides a framework for understanding how the resource curse manifests in the GCC and affects the long-term sustainability of oildriven growth. The results of this study reveal that while market capitalization and oil rents provide short-term boosts to GDP growth, their long-term sustainability is limited without comprehensive reforms that address the structural issues posed by oil dependency. Consistent with the resource curse theory, the continued reliance on oil rents hinders broader economic development, as it stifles innovation, reduces the competitiveness of non-oil sectors, and increases economic volatility. External and domestic investments emerge as key drivers of sustainable growth, highlighting the importance of external investments and domestic capital formation in reducing dependency on oil revenues. Additionally, inflation and unemployment are shown to be significant challenges, emphasizing the need for effective policies to manage these issues and foster a more resilient economy. By analyzing the shortand long-term impacts of market capitalization, oil rents, and other socio-economic variables, this research offers valuable insights into strategies that can help policymakers design more balanced and diversified economic systems in the GCC. These insights align with the region’s long-term development visions, which seek to escape the resource curse by transitioning towards a more diversified, innovation-driven economy. 2. Literature Review Economic diversification is essential for oil-dependent economies like those in the GCC to mitigate the risks associated with oil price fluctuations and achieve sustainable growth. The ‘resource curse’ theory, outlined by Sachs and Warner (2001), describes how over-reliance on natural resources can stifle broader economic development. This happens because dependence on one resource limits innovation, economic diversification, and institutional growth, creating a cycle of vulnerability to market shifts. GCC countries, heavily reliant on oil, are particularly exposed to this risk, making diversification an imperative Economies 2024,12, 287 3 of 29 for their long-term economic health. Diversification strategies are key to reducing macroeconomic volatility and building resilience against external shocks. Van der Ploeg (2011) argues for transitioning from oil-dependent economic structures to more varied and diversified models, highlighting that this shift helps reduce vulnerability to global oil market fluctuations. The World Bank (2022) supports this view, emphasizing that economies reliant on natural resources need to expand into non-oil sectors like manufacturing and services to stabilize and sustain long-term growth. These sectors can provide more consistent economic output, shield countries from the volatility of resource markets, and pave the way for broader economic stability. Human capital development and business dynamism are critical drivers of successful diversification. A well-educated, skilled workforce is crucial for expanding into non-oil industries such as technology, healthcare, and renewable energy. Countries that invest in their human capital—through education, training, and healthcare—are better positioned to transition toward non-resource-based economies. For example, Oman has focused on enhancing education and workforce capabilities to support its economic diversification efforts, while Indonesia’s human capital investments have facilitated growth in its manufacturing and service sectors. These case studies demonstrate that strengthening human capital is essential for reducing dependency on a single resource and fostering broader economic growth. Innovation and entrepreneurship further accelerate diversification efforts. Albassam (2015) points out that fostering a culture of innovation is vital for GCC countries as they transition from oil-based economies. Encouraging entrepreneurship enables the development of new industries and technologies, which are necessary for creating a diverse and competitive economy. The GCC’s long-term strategic plans, such as Saudi Arabia’s Vision 2030, focus on reducing oil dependence by promoting investment in emerging sectors like renewable energy, healthcare, education, and technology. By supporting entrepreneurs and small and medium-sized enterprises (SMEs), these plans aim to create a more dynamic and innovative economy capable of generating sustainable growth. This shift is particularly critical for GCC economies, which face the challenge of balancing current oil revenues with the need to invest in future industries. Vision 2030 and similar strategies reflect the understanding that sustained economic growth requires more than just oil exports—it requires a diversified economic base supported by skilled labor, innovation, and a robust business environment. By creating conducive conditions for new industries to flourish and reducing reliance on oil, the GCC countries are working to ensure a more resilient economic future. 2.1. Financial Markets and Economic Expansion The relationship between financial market development and economic growth is welldocumented, with market capitalization acting as a key indicator of a country’s financial maturity. Well-developed financial markets facilitate efficient capital allocation, which in turn drives productivity and fosters long-term economic expansion. Levine and Zervos (1998) argue that when financial markets function effectively, they help guide investments into productive areas, thereby promoting overall economic growth. This makes financial market development a crucial aspect of economic strategy for countries seeking sustained growth. Recent studies further confirm this relationship in emerging markets. Osaseri and Osamwonyi (2019) demonstrate that stock market development has a significant positive impact on economic growth in BRICS countries, reinforcing the idea that financial maturity plays a vital role in facilitating growth. These findings align with the economic goals of GCC countries, where financial market development could similarly support diversification efforts by providing capital for non-oil sectors, promoting long-term economic stability. However, the growth of financial markets must be paired with strong regulatory frameworks to ensure stability and prevent potential risks. Naceur and Ghazouani (2007) emphasize that in regions such as the Middle East and North Africa (MENA), the expansion of financial markets does not always directly contribute to economic growth, especially in Economies 2024,12, 287 4 of 29 environments with weak regulatory oversight. Inadequately regulated financial systems can lead to market instability, as shown by Kaminsky and Schmukler (2003), who highlight that financial liberalization, when combined with weak regulatory oversight, may introduce short-term instability. Demirgüç-Kunt et al. (2013) similarly warn that rapid financial market growth, if left unchecked in weak regulatory settings, can lead to economic instability, demonstrating the importance of sound governance in maintaining financial stability. In the context of the GCC, where economies are working toward diversification, financial market development plays an especially critical role. Grassa and Gazdar (2014) provide empirical evidence showing that robust financial systems are vital in supporting economic diversification strategies in resource-dependent economies like those in the GCC. Well-functioning financial markets supply the capital and liquidity necessary for developing non-oil sectors, helping to reduce the reliance on oil revenues. These markets also attract foreign investment, further bolstering economic growth and helping the GCC countries transition to more sustainable, diversified economies. Ensuring that financial market growth is supported by strong regulatory frameworks is essential for GCC countries aiming to use financial development as a tool for diversification. As the region seeks to expand beyond oil, effective financial markets will be instrumental in funding the growth of new sectors and supporting long-term economic stability. 2.2. The Influence of Oil Rents on Economic Growth While oil rents have been a major source of revenue for GCC economies, they present significant challenges to economic diversification. The resource curse theory, as outlined by Sachs and Warner (2001), suggests that countries rich in oil often experience slower economic growth due to the crowding out of other productive sectors. This phenomenon occurs as oil revenues dominate the economy, leaving little room for the development of non-oil sectors like manufacturing or services. Fuinhas et al. (2015) reinforce this argument, showing that oil rents tend to depress economic growth in both the short and long term, reinforcing the notion that oil wealth, while lucrative in the short term, often hinders sustainable growth. This highlights the critical need to reduce dependency on oil rents and promote economic diversification to build more resilient economies. Effective governance is a key factor in mitigating the negative effects of oil dependency. Matallah and Matallah (2016) emphasize that governance reforms are essential for overcoming the resource curse, particularly in oil-rich economies. Strong governance ensures that oil wealth is used strategically to promote long-term economic diversification and reduce the risks associated with oil price fluctuations. By improving transparency, accountability, and regulatory frameworks, governance reforms can help guide oil-dependent countries towards more balanced and sustainable growth. Fuinhas et al. (2015) expand on this by demonstrating that while oil consumption can boost economic growth in the short run, oil rents depress growth in the long run. This aligns with the broader resource curse theory, which explains how the over-reliance on oil revenues can crowd out the development of other industries, ultimately restricting broader economic development. The study underlines the importance of moving away from oil dependency and implementing diversification strategies to counter the long-term negative impacts of oil rents on economic performance. Grassa and Gazdar (2014) offers a nuanced view of the rentier state and resource curse narratives, particularly regarding the GCC countries. He argues that while the resource curse framework predicts detrimental effects of oil rents on economic growth, the GCC countries have not experienced the full extent of these negative consequences. They contends that the GCC countries, unlike many other oil-dependent nations, have managed to mitigate some of the worst effects of the resource curse, potentially due to better governance and more strategic use of oil revenues. This suggests that while oil rents have historically dominated their economies, the GCC’s experience with the resource curse has been comparatively less damaging. Economies 2024,12, 287 5 of 29 Despite these relatively positive outcomes, the fundamental challenge remains that continued reliance on oil rents restricts long-term economic growth potential. The GCC countries must prioritize economic diversification to secure sustainable development. As emphasized by Matallah and Matallah (2016), governance reforms are crucial to ensuring that oil revenues are invested strategically in sectors that promote diversification and economic resilience, thereby reducing the risk of future volatility and enabling sustainable growth across the region. 2.3. Socio-Economic Factors and Economic Growth in the GCC 2.3.1. Inflation and Economic Growth Inflation can adversely impact economic growth by eroding purchasing power and distorting price signals. Chimobi (2010) highlights that inflation can destabilize long-term economic prospects, particularly in oil-dependent economies like the GCC. Moderate inflation; however, can support growth, as noted by Khan and Ssnhadji (2001), who identify inflation thresholds (7–11%) that are conducive to growth in developing economies. Additionally, Barro (1996) emphasizes that inflation can have a detrimental effect on economic growth, with an increase of 10 percentage points in inflation leading to a reduction in real per capita GDP growth by 0.2–0.3 percentage points annually. Inflation also negatively impacts the investment-to-GDP ratio, reducing it by 0.4–0.6 percentage points. Although the short-term effects may seem modest, over a 30-year period, sustained inflation can lower real GDP by 4–7%, underscoring the importance of price stability for long-term economic prosperity. In the context of the GCC, where economies are transitioning towards diversification, managing inflation is crucial. The effects of inflation on investment and growth, as described by Barro (1996) and Fischer (1993), are particularly relevant as the GCC countries work to attract foreign and domestic investment into non-oil sectors. Controlling inflation can create a more stable economic environment that encourages long-term investment, fosters human capital development, and supports innovation, all of which are essential for achieving sustainable growth. 2.3.2. Unemployment and Economic Growth Unemployment remains a significant challenge in the GCC, particularly due to labor market rigidities. High unemployment signals underutilization of human capital, which hampers economic efficiency. Fasano and Goyal (2004) emphasize the importance of labor market flexibility and aligning education with market needs to address unemployment and support sustainable growth. Economic growth in the GCC is closely tied to employment trends, with increasing attention being paid to how growth affects job creation. Ben-Salha and Zmami (2021) examine the employment intensity of growth across six GCC countries from 1970 to 2017. Their study reveals that employment elasticities (the responsiveness of employment to growth) range between 0.4 and 0.6, showing an upward trend over time. This indicates: economic growth has had a moderate but growing impact on employment generation in the GCC; long-term employment intensity is positively influenced by factors, such as trade liberalization; the increasing contribution of the services sector to GDP, growth in the working-age population, and urbanization. However, macroeconomic volatility exerts a negative impact on employment intensity over time. In the short term, trade liberalization and natural resource rents show adverse but relatively weak effects on job creation. Blanchard and Wolfers (2000) discuss the significant role that external shocks and institutional frameworks play in shaping economic outcomes, particularly in the context of unemployment in European economies. Their analysis highlights how adverse shocks, such as oil price volatility, coupled with inadequate institutional responses, can exacerbate unemployment rates and hinder long-term economic growth. This perspective is particularly relevant to the GCC economies, which face similar vulnerabilities due to their reliance on oil revenues. Just as Blanchard and Wolfers argue for the importance of robust Economies 2024,12, 287 6 of 29 institutions in mitigating these effects, GCC countries must strengthen their institutional frameworks to manage the economic instability brought about by external shocks, ensuring more sustainable economic development These findings highlight the importance of implementing policies that not only promote economic growth but also tackle the underlying structural challenges affecting employment generation. This analysis highlights the importance of economic diversification in the GCC, as sectors such as services contribute more to job creation compared to oil-dominated sectors. For the GCC countries to reduce their reliance on oil rents and foster inclusive growth, it is essential to develop policies that encourage service sector expansion, enhance trade liberalization, and manage urbanization effectively. By doing so, they can generate more employment opportunities, which is critical to the region’s socio-economic stability. 2.3.3. Human Development and Economic Resilience Human development, as measured by the Human Development Index (HDI), plays a critical role in influencing economic growth, particularly in resource-dependent economies like those in the GCC. Grubaugh (2015) demonstrates that economic growth, when viewed through the lens of HDI rather than traditional GDP per capita, provides a more comprehensive understanding of a nation’s development. His findings suggest that while population growth and initial GDP are important drivers, HDI captures broader aspects of growth by incorporating life expectancy, education, and living standards. This approach indicates that for sustainable growth, GCC countries must focus not just on GDP expansion, but also on improving human development outcomes, which are essential for long-term stability and prosperity. Human capital development is particularly important in the GCC, as highlighted by Abdeldayem et al. (2021). Their study reveals that the low levels of investment in research and development (R&D) and the limited proportion of workers engaged in knowledgeintensive sectors are major obstacles to achieving innovation-led growth. This creates a barrier to economic diversification, as the lack of focus on human capital development inhibits the GCC from achieving a competitive edge in non-oil sectors. Public governance also plays a critical role in determining the success of human capital development in driving economic growth. Al-Naser and Hamdan (2021) find that governance indicators—such as regulatory quality and government effectiveness—are significantly correlated with GDP growth. Their study reveals that improvements in governance and human development work in tandem to foster stronger economic outcomes. This highlights the need for effective governance structures to maximize the benefits of human capital investments in the GCC. The collective findings from these studies emphasize that human development, governance, and innovation are pivotal to the long-term economic success of the GCC countries. While these nations have historically relied on oil rents, their future economic stability will depend on their ability to invest in human capital, foster innovation, and strengthen governance frameworks. As shown by Grubaugh (2015), a focus on improving HDI, in conjunction with strong governance, can provide the foundation for more sustainable, diversified growth in the GCC region. 2.3.4. Political Stability and Economic Growth Political stability is a key enabler of economic growth, particularly in the GCC region. Stable political environments create conditions conducive to investment and long-term economic planning. Abdalla and Abdelbaki (2014) note that political stability in countries like Bahrain and the UAE fosters the growth of the FDI and exports. However, political instability, as highlighted by Aisen and Veiga (2013), can reduce productivity growth by deterring long-term investment. Hvidt (2013) and Rajan and Zingales (2003) emphasize that political and economic obstacles continue to hinder the successful implementation of diversification efforts in the GCC. Political will is crucial in overcoming barriers to financial Economies 2024,12, 287 7 of 29 reforms and economic diversification in resource-dependent economies like those in the GCC. Ross (2018) also underscores the political dynamics related to resource dependence, particularly in oil-rich nations, further highlighting the importance of governance reforms alongside economic reforms. 2.3.5. Gross Capital Formation (GCF) and Economic Growth Gross capital formation (GCF), representing investments in physical capital such as infrastructure, machinery, and equipment, is a critical driver of economic growth. GCF enhances a country’s productive capacity, which, according to Solow’s (1964) growth model, directly influences long-term economic performance. This is particularly relevant in economies transitioning from resource dependence, such as those in the GCC, where capital investments are essential for diversification and reducing reliance on oil revenues. Empirical evidence supports the positive relationship between GCF and economic growth. Barro (1991) found a strong correlation between GCF and GDP growth, especially in countries seeking economic diversification. In the context of the GCC, investments in physical capital not only build infrastructure but also stimulate innovation and foster resilience, allowing these economies to adapt to global shifts in energy markets. Topcu et al. (2020) further emphasize the importance of GCF in shaping economic growth across various income levels. Their study of 124 countries reveals that capital accumulation, combined with energy consumption and natural resources, significantly impacts national productivity. In high-income countries, GCF positively influences GDP, but in low-income countries, its effect is less pronounced, indicating that additional factors such as institutional strength, are necessary to maximize GCF’s potential. In examining the role of investment, Gylfason and Zoega (2001) argue that abundant natural resources can crowd out physical capital, thus inhibiting economic growth. In conclusion, GCF is a vital component of economic development, particularly for countries like those in the GCC, which are working to diversify their economies. The accumulation of physical capital drives growth, but its effectiveness depends on regional and institutional contexts, underscoring the need for tailored policies that align with specific economic conditions. 2.3.6. The Role of Foreign Direct Investment (FDI) Foreign direct investment (FDI) is widely recognized as a key driver of economic growth, particularly in developing and resource-dependent economies. Research by Borensztein et al. (1998) underscores the positive impact of FDI on GDP growth, particularly through technology transfer, managerial expertise, and increased productivity. In the Gulf Cooperation Council (GCC) economies, FDI plays a critical role in diversification efforts by providing external capital for developing non-oil sectors such as finance, tourism, and infrastructure (Alfaro et al. 2004). However, the success of FDI in boosting growth is contingent upon the absorptive capacity of the host country—the ability to effectively utilize FDI through factors like human capital and institutional quality (Carkovic and Levine 2005). The effectiveness of FDI is often influenced by domestic conditions. For instance, Blomström et al. (2003) emphasize that robust institutions and a favorable business environment are necessary to maximize FDI’s benefits. The presence of well-developed financial markets, efficient regulatory frameworks, and skilled labor are crucial in amplifying FDI’s positive effects on economic growth. In the GCC context, Al-Iriani (2007) explores the relationship between FDI and economic growth using heterogeneous panel analysis. His findings reveal a bi-directional causality between FDI and GDP, indicating that FDI promotes economic growth, and growing economies, in turn, attract more FDI. This is particularly relevant in the GCC, where countries have actively opened their economies to foreign investment as part of broader efforts to diversify away from oil dependence. Al-Iriani emphasizes the role of FDI in technological diffusion and stresses the need for continued improvements in infrastructure, human capital, and financial market development to attract and maximize FDI. Economies 2024,12, 287 8 of 29 The studies collectively demonstrate that FDI can have a significant positive impact on economic growth, but the magnitude of this impact is largely dependent on domestic conditions. For countries like those in the GCC, where FDI inflows have grown substantially in recent years, there is a clear need for policies that enhance absorptive capacities, such as investing in education, infrastructure, and institutional reforms. While FDI plays a crucial role in promoting economic growth and diversification, the effectiveness of this relationship is shaped by both internal and external factors. 3. Methodology This study uses a comprehensive econometric approach to examine the relationship between market capitalization, oil rents, and other macroeconomic variables on GDP growth in the GCC countries from 2000 to 2022. Both static and dynamic panel data models are applied to account for short-term fluctuations and long-term equilibrium dynamics in these resource-dependent economies. 3.1. Data Sources The data for this study are sourced from authoritative institutions, including the World Bank, the International Monetary Fund (IMF), and various national statistical agencies. These sources are widely recognized for their reliability and rigor in compiling macroeconomic indicators, which ensures the credibility of the variables used in our analysis. The key variables, such as GDP growth, oil rents, foreign direct investment (FDI), and inflation, are derived from these institutions, providing a consistent and accurate dataset that reflects both national and international economic trends. The World Bank and IMF databases offer data spanning several decades, allowing for comprehensive longitudinal analysis that is essential for studying trends and fluctuations in the GCC economies. These organizations follow standardized procedures in data collection, including cross-referencing national statistics and applying international guidelines to harmonize data from various sources. This ensures that the data are comparable across countries and, over time, a critical factor when analyzing panel data from different GCC nations. To further assess the quality of the data, we acknowledge the importance of timeliness and accuracy—particularly considering global events such as the 2008 financial crisis and the COVID-19 pandemic. Both the World Bank and IMF update their data regularly to capture real-time changes in economic performance, ensuring that any sudden shocks or shifts are reflected as soon as possible. During these crises, these institutions were able to swiftly release emergency reports and update forecasts to provide policymakers and researchers with up-to-date information. Although some time lags in data reporting are inevitable, particularly for more detailed national data, both organizations prioritize updating key economic indicators such as GDP growth, inflation, and oil rents to reflect the most current state of the global economy. Their data collection methodologies follow strict verification protocols, ensuring high accuracy. These standards are vital, especially during periods of uncertainty, when accurate data are critical for making informed policy decisions. Furthermore, the rigorous cross-validation process employed by the World Bank and IMF, which involves comparing national data sources and international guidelines, minimizes inconsistencies and enhances the overall reliability of the dataset. This meticulous approach ensures that the data are not only timely but also robust, providing a solid foundation for our econometric analysis. 3.2. Empirical Strategy and Model Justification The empirical strategy begins by applying fixed effects (FE) and random effects (RE) models to assess the cross-sectional and temporal dynamics of the GCC economies. The Hausman test (Hausman 1978) was employed to determine the preferred model, with the Economies 2024,12, 287 15 of 29 The diminishing impact of Oil Rent (OR) across models suggests a growing need to reduce dependency on natural resources, supporting the view that reliance on natural resources alone is not a sustainable growth strategy. While OR is statistically significant in Model 1, its significance diminishes as more variables are introduced in Models 2 and 3, aligning with the broader literature on the resource curse (e.g., Sachs and Warner 2001). The expanded regression models reveal that while natural resources remain crucial for short-term growth, the inclusion of additional variables highlights other significant drivers. TB and GCF emerge as key factors supporting economic performance, emphasizing the importance of external trade and domestic capital investment. The positive impact of FDI reinforces the role of external capital inflows, and the significant relationship between CPI and GDP growth demonstrates the critical need for effective inflation management. Overall, these results suggest that the GCC economies cannot rely solely on natural resources for long-term sustainable growth. A more comprehensive approach, leveraging trade, investment, and inflation control, is necessary to achieve long-term economic stability and resilience. Although Market Capitalization remains positively correlated but insignificant, this might indicate that the size of financial markets has a more indirect or long-term influence on economic growth. 4.6. Cointegration and Long-Run Relationships Table 6presents the results of the Kao Panel Cointegration Test, confirming the existence of long-run equilibrium relationships between key economic variables in the GCC countries. These variables include GDP growth, Mcap, OR HDI, TB, GCF, FDI, CPI, UN, and PS. With p-values below 0.05 across several versions of the Dickey–Fuller tests, the results suggest that despite short-term fluctuations, these variables move together over time, indicating stable and persistent economic relationships. Table 6. Panel cointegration analysis: Kao Test results. Cointegration Test Test Statistic p-Value Modified Dickey–Fuller Test −1.9253 0.0271 Dickey–Fuller Test −2.6352 0.0042 Augmented Dickey–Fuller Test −2.4585 0.0070 Unadjusted Modified Dickey–Fuller −2.1247 0.0168 Unadjusted Dickey–Fuller Test −2.7095 0.0034 Note: p-values below 0.05 indicate rejection of the null hypothesis, suggesting the presence of long-term equilibrium relationships among the variables. This cointegration highlights the importance of considering the long-term interplay between these variables. Even though short-term shifts might occur, the long-run equilibrium suggests that these economic indicators are tied together by underlying forces that support stable growth in the region. The Kao Panel Cointegration Test results complement the short-term findings from Table 5. In Table 5, variables such as TB, GCF, FDI, and CPI played significant roles in short-term GDP growth. The cointegration test confirms that these variables continue to have long-term relevance. The importance of TB and GCF for both short-term and longterm growth emphasizes the role of external trade and domestic investment in sustaining economic performance in the GCC. FDI and CPI also remain vital in the long run, reinforcing their roles in supporting sustained economic growth. FDI highlights the importance of external capital inflows, while CPI reflects the need for careful inflation management. The persistence of these relationships over time suggests that focusing on improving trade, investment, and inflation control will be essential for the GCC’s long-term economic stability. Economies 2024,12, 287 16 of 29 Role of Oil Rent and the Resource Curse Oil Rent, while significant in the short term, shows a diminishing impact as more variables are introduced in the long-run analysis. This signals the need for the GCC economies to gradually reduce their reliance on oil as a driver of growth. The long-run equilibrium shows that other factors, such as FDI, CPI, and GCF, play increasingly important roles, underscoring the necessity of diversifying the economy beyond natural resources. Variables like UN and PS, which were insignificant in the short-term analysis in Table 5, also appear in the long-term cointegration relationships. This suggests that, while they may not have immediate effects on GDP growth, these factors contribute to the long-term health and stability of the economy. Persistent unemployment, for example, could undermine growth in the long run, and political stability is essential for sustaining investor confidence and economic consistency over time. The long-run equilibrium relationships among these variables reinforce the broader need for diversified economic policies. Focusing on short-term gains through oil revenue alone will not ensure sustainable growth. Instead, investing in financial markets, human capital, trade, and inflation control can help build a more resilient economic structure. Although HDI was statistically insignificant in the short-term models, its inclusion in the long-term analysis suggests that human capital investments, such as improvements in education and healthcare, are crucial for long-term growth. This supports the argument that focusing on human development, even if it does not yield immediate results, will be critical for sustainable growth in the future. Future research may further investigate the delayed effects of human capital investments, particularly through longitudinal studies that track the outcomes of reforms like Vision 2030. This would provide a more comprehensive understanding of the timeline for human capital development to influence GDP growth in oil-dependent economies. In conclusion, the Kao Panel Cointegration Test results confirm that key variables are tied by long-run equilibrium relationships in the GCC economies. While OR continues to provide short-term growth, the long-term sustainability of the region depends on diversifying beyond oil and investing in financial development, trade, inflation control, and human capital. Policymakers should prioritize these areas to ensure long-term resilience and growth, positioning the GCC economies to better manage external shocks and achieve sustained prosperity. 4.7. Event Study and Dummy Variables Table 7presents the results of an event study regression, which includes dummy variables to capture the impact of significant global economic disruptions, such as the 2008 Financial Crisis and the 2020 COVID-19 pandemic, on GDP growth in the GCC countries. The findings demonstrate that these crises had statistically significant negative effects on GDP growth, with the event dummy in Model 3 showing a highly significant coefficient of − 3.683 * (p< 0.01). This highlights the profound economic challenges that arise when oildependent economies are exposed to external global shocks. The results align with broader findings in the literature regarding the vulnerability of resource-dependent economies to external shocks. This supports the findings in Table 7, where the 2008 Financial Crisis and the 2020 COVID-19 pandemic had substantial negative effects on GDP growth in the GCC, demonstrating the region’s heightened exposure to external disruptions. The results in Table 7also reflect the vulnerabilities of oil-dependent economies like the GCC to such shocks, as evidenced by the diminishing significance of OR across the models. Model 1 shows a positive but weakly significant relationship between OR and GDP growth (0.0675 *, p< 0.1), but this effect becomes insignificant in Models 2 and 3 as other economic factors, such as FDI and CPI, are introduced. This decline in significance aligns with the concept of the resource curse, where economies heavily reliant on natural resources often struggle to sustain long-term economic growth due to their vulnerability to external shocks and price fluctuations. Economies 2024,12, 287 17 of 29 Table 7. Event study regression results. Variable Model 1 (Basic) Model 2 (Extended) Model 3 (Complete) Mcap 0.0112 0.0105 0.0157 ** (0.00881) (0.00841) (0.00773) OR 0.0675 * −0.000889 0.0558 (0.0354) (0.0384) (0.0428) HDI −0.651 −4.958 −4.392 (7.413) (7.168) (6.462) TB 0.150 *** 0.0867 ** (0.0401) (0.0436) GCF 0.120 ** 0.0889 (0.0596) (0.0678) FDI 0.485 *** (0.144) CPI 0.478 *** (0.132) UN −0.236 (0.251) PS 0.0246 (0.0195) Event Dummy −1.630 −1.292 −3.683 *** (1.170) (1.120) (1.046) Constant 2.307 4.606 −2.427 (6.347) (6.089) (6.052) Observations 138 138 138 R-squared 0.053 0.144 0.381 Note: Standard errors in parentheses. ***, **, and * indicate statistical significance at the 1%, 5%, and 10% levels, respectively. The resource curse is particularly relevant to the GCC economies, where oil has traditionally been the primary driver of economic growth. As shown in Table 7, the impact of OR diminishes as more variables are included in the analysis, signaling that oil revenues alone are not sufficient to protect these economies from external shocks like the 2008 Financial Crisis and the 2020 COVID-19 pandemic. The GCC economies, despite their abundant oil resources, face greater exposure to global disruptions because of their heavy reliance on oil, which subjects them to fluctuations in global oil prices and demand. The negative effects observed in Table 7support the resource curse hypothesis, reinforcing the need for diversification strategies to mitigate the risks associated with dependence on natural resources. This is reflected in Table 7, where the negative effects of global disruptions highlight the need for economic diversification to mitigate the risks associated with dependence on oil. As reliance on oil revenues diminishes, other variables take on more importance in explaining GDP growth. FDI becomes highly significant in Model 3 (0.485 *, p< 0.01), highlighting the critical role of external capital inflows in supporting growth, particularly during periods of global disruption. CPI also plays a significant role (0.478 *, p< 0.01), reflecting the importance of inflation management in maintaining economic stability amid external shocks. Additionally, TB remains an important factor, with a significant positive effect on GDP growth (0.0867, p< 0.05), demonstrating that trade performance is key to sustaining economic growth, even during periods of global turmoil. Mcap becomes statistically significant in Model 3 (0.0157, p< 0.05), indicating the growing relevance of financial market development as part of a diversified economic framework. The concept of the resource curse is further reinforced by the results in Table 7, which show that the significance of OR diminishes as other non-oil variables become more important in driving GDP growth. This shift reflects the vulnerability of oil-dependent economies, which struggle to maintain stability when external shocks affect global oil demand and prices. The negative impact of global disruptions on GDP growth underscores Economies 2024,12, 287 18 of 29 the need for economic diversification in the GCC to reduce reliance on oil revenues and build a more resilient economic foundation. By attracting foreign investment, improving trade performance, and maintaining inflation control, the GCC can develop a more robust and resilient economic structure, less susceptible to external shocks and fluctuations in oil prices. The significant positive coefficients for FDI, CPI, and TB in Model 3 highlight the importance of economic diversification and the development of other sectors to sustain growth and reduce exposure to the resource curse. These findings align with those of Al-Mulali and Sab (2013), who emphasize the importance of foreign capital inflows and inflation management in stabilizing resource-dependent economies. 4.8. Advanced Econometric Analysis: Fixed and Random Effects Models Table 8compares the results from the fixed effects (FE) and random effects (RE) models, used to analyze the relationship between key economic variables and GDP growth in the GCC countries. The Hausman test, as referenced in Table 9, indicates a preference for the fixed effects model, suggesting that unobserved country-specific factors, such as governance, institutional structures, or unique economic policies, could bias the estimates in the random effects model. This makes the fixed effects model more appropriate, as it controls for these factors, providing more reliable and consistent estimates. Table 8. Fixed and random effects regression results. Variable Fixed Effects (FE) Random Effects (RE) Mcap 0.0165 * 0.0109 (0.00926) (0.00794) OR 0.195 *** 0.0607 (0.0743) (0.0446) HDI 1.526 −5.752 (6.939) (6.731) TB 0.0182 0.0972 ** (0.0530) (0.0454) GCF 0.0470 0.105 * (0.0946) (0.0620) FDI 0.360 ** 0.435 *** (0.169) (0.150) CPI 0.321 ** 0.344 *** (0.136) (0.132) UN −1.756 *** −0.306 (0.661) (0.261) PS 0.0798 * 0.0220 (0.0433) (0.0203) Constant −7.125 −0.757 (7.952) (6.296) Observations 138 138 R-squared 0.339 Number of Countries 6 6 Note: Standard errors in parentheses. ***, **, and * indicate statistical significance at the 1%, 5%, and 10% levels, respectively. Table 9. Hausman (1978) specification test. Statistic Value Chi-Square Test Value 19.47 p-value 0.0215 The results from the fixed effects model highlight the significance of OR in driving GDP growth in the GCC. With a positive and statistically significant coefficient (0.195 *, p< 0.01) , oil revenues remain central to economic performance, despite ongoing efforts Economies 2024,12, 287 19 of 29 toward diversification. In contrast, OR in the random effects model shows a weaker relationship (0.0607) and loses statistical significance. This suggests that oil’s contribution to growth is more context-dependent, influenced by specific country characteristics. Another key variable, FDI, emerges as a crucial driver of growth, particularly in the fixed effects model (0.360, p< 0.05). This finding underscores the importance of attracting foreign investment, which can fuel long-term growth and contribute to the diversification of the economy. Similarly, GCF, though not statistically significant in the fixed effects model (0.0470), suggests that domestic investment remains important for economic expansion. Inflation dynamics, as measured by the CPI, show a positive and significant impact on GDP growth in both models, with the fixed effects model coefficient at 0.321 (p< 0.05). This indicates that inflationary pressures, possibly reflecting increased demand during economic growth phases, are positively correlated with GDP growth in the region. Managing inflation effectively remains a key consideration for policymakers, especially in economies that are transitioning from oil dependency to more diversified sources of income. UN has a significantly negative impact on GDP growth in the fixed effects model ( − 1.756 *, p< 0.01), indicating that high unemployment rates present a major obstacle to economic development. This suggests that addressing labor market inefficiencies and creating job opportunities should be central to policy efforts aimed at fostering long-term growth. The lack of significance for UN in the random effects model further supports the use of fixed effects for more accurate insights into the role of unemployment. PS has a moderate positive effect on GDP growth in the fixed effects model (0.0798, p< 0.1) , reinforcing the notion that stable political environments contribute to better economic outcomes. While the relationship is weaker compared to other variables, it remains an important factor, particularly when considering the long-term attractiveness of the GCC for foreign investors. These findings align with the concept of the resource curse, which posits that economies heavily reliant on natural resources like oil often face growth challenges due to volatility in global prices and demand. The diminishing role of OR as more variables are introduced in the analysis, combined with the increasing significance of FDI, CPI, and TB, supports the argument for economic diversification. GCC economies must continue to reduce their dependence on oil revenues and focus on developing other sectors to ensure long-term economic resilience. By emphasizing foreign investment, trade, inflation control, and labor market reforms, GCC policymakers can mitigate the risks associated with the resource curse. The insights gained from the fixed effects model demonstrate the importance of addressing structural issues, such as unemployment and political stability, to create a more sustainable and diversified economic foundation. These strategies are essential to achieving sustained growth and reducing the vulnerability of the GCC economies to external shocks and fluctuations in oil prices. 4.9. Diagnostic Tests and Robustness of Econometric Results To ensure the robustness and reliability of the econometric results, several diagnostic tests were conducted to detect potential issues in the model specifications. The results of these tests, as outlined in Tables 10–13, confirm that the necessary corrections were applied, addressing concerns related to heteroskedasticity, multicollinearity, and autocorrelation, ensuring the validity of the findings. Table 10. Breusch-Pagan/Cook-Weisberg test for heteroskedasticity. Test Statistic p-Value Breusch-Pagan/Cook-Weisberg Test 11.45 0.0007 Economies 2024,12, 287 20 of 29 Table 11. Variance inflation factor (VIF) analysis. Variable VIF Mcap 2.31 OR 1.89 HDI 3.14 TB 1.73 GCF 1.62 FDI 2.02 CPI 1.95 UN 2.45 PS 1.87 Table 12. Wooldridge test for autocorrelation. Statistic Value F-Statistic 4.19 p-value 0.0458 Table 13. Modified Wald test for groupwise heteroskedasticity. Statistic Value Chi-Square Test Value 25.36 p-value 0.0000 The first test conducted was the Breusch-Pagan/Cook-Weisberg test for heteroskedasticity (Table 10). The test revealed the presence of heteroskedasticity, as indicated by a statistically significant p-value of 0.0007. This result suggests that the variance of the residuals was not constant across observations, which could lead to unreliable coefficient estimates if left unaddressed. To mitigate this issue, robust standard errors were applied to the model. This adjustment corrected for heteroskedasticity, ensuring that the standard errors are reliable, and allowing for more accurate inferences regarding the significance of the model’s coefficients. To assess the presence of multicollinearity among the explanatory variables, a Variance Inflation Factor (VIF) analysis was performed (Table 11). The results show that all VIF values were well below the conventional threshold of 5, with the highest being 3.14 for HDI, indicating that multicollinearity was not a significant concern. This confirms that the estimated coefficients are not inflated or distorted by high correlations between the independent variables, ensuring the reliability of the regression results. Next, the Wooldridge test for autocorrelation was applied to check for first-order autocorrelation in the panel data (Table 12). The test produced a statistically significant result, with an F-statistic of 4.19 and a p-value of 0.0458, indicating the presence of autocorrelation. Autocorrelation can lead to biased standard errors, which could result in incorrect inferences. To address this, the Arellano–Bond generalized method of moments (GMM) approach was implemented. This method corrects for both autocorrelation and endogeneity, ensuring that the coefficient estimates remain consistent and that the standard errors are robust. Finally, the Modified Wald test for groupwise heteroskedasticity (Table 13) was conducted, yielding a chi-square value of 25.36 and a p-value of 0.0000, confirming the presence of significant groupwise heteroskedasticity. This form of heteroskedasticity suggests that the variance of the residuals varies across different groups (e.g., countries in the panel data). Similar to the Breusch-Pagan test results, robust standard errors were applied to correct for this heteroskedasticity, ensuring that the model provides reliable and unbiased coefficient estimates. The combined results from these diagnostic tests reinforce the validity of the model specifications. By applying robust standard errors to address heteroskedasticity and using Economies 2024,12, 287 21 of 29 the Arellano–Bond GMM approach to correct for autocorrelation and endogeneity, the econometric analysis ensures that the findings are statistically sound. The absence of multicollinearity further strengthens the confidence in the coefficient estimates, confirming that the relationships between the key economic variables and GDP growth are reliable. These robustness checks demonstrate that the potential biases related to heteroskedasticity, multicollinearity, and autocorrelation have been properly addressed. As a result, the conclusions drawn from the econometric models are valid and provide a reliable basis for policy interpretation. The adjustments made to correct these issues ensure that the findings are robust, making the analysis suitable for guiding economic policy decisions in the GCC countries. 4.10. Dynamic GMM Results Table 14 presents the results of the dynamic GMM model, which examines the longterm dynamics of GDP growth in the GCC countries. The dynamic GMM approach is particularly well-suited for addressing issues of endogeneity and autocorrelation in panel data, allowing for more robust insights into the key factors influencing economic growth. Table 14. Dynamic generalized method of moments (GMM) regression results. Variable GMM Estimates Lagged GDP Growth 0.321 *** (0.0945) Mcap 0.0126 * (0.00758) OR 0.145 ** (0.0612) HDI −2.578 (5.963) TB 0.0589 ** (0.0285) GCF 0.0893 * (0.0532) FDI 0.297 ** (0.143) CPI 0.262 ** (0.127) UN −1.254 *** (0.432) PS 0.0347 ** (0.0170) Constant 0.576 (5.738) Observations 138 Number of Instruments 15 Arellano–Bond Test (AR1 p-value) 0.0352 Arellano–Bond Test (AR2 p-value) 0.1897 Hansen Test (p-value) 0.2764 Note: Standard errors in parentheses. ***, **, and * indicate statistical significance at the 1%, 5%, and 10% levels, respectively. The significant positive coefficient for Lagged GDP Growth (0.321 *, p< 0.01) indicates a strong momentum effect within the GCC economies. This suggests that past economic performance plays an essential role in shaping current growth, reinforcing the idea that the economic trajectory of these countries is heavily influenced by sustained growth trends. This persistence effect is characteristic of dynamic models and emphasizes the importance of maintaining economic momentum. The positive and significant effect of OR (0.145, p< 0.05) highlights the continued importance of oil revenues in driving short-term growth. However, the potential diminishing Economies 2024,12, 287 22 of 29 returns associated with oil rents point to the risks of resource dependency. As the region remains highly reliant on natural resources, particularly oil, the results suggest that this dependence may not be sustainable in the long run. This aligns with the resource curse hypothesis, where economies dependent on natural resource extraction often experiences slower long-term growth due to external price fluctuations and declining returns over time. These findings reinforce the need for economic diversification in the GCC to reduce vulnerability to global oil price shocks and ensure more sustainable growth. FDI emerges as a key driver of economic growth in the region, with a positive and significant coefficient (0.297, p< 0.05). This underscores the importance of attracting external investment to support infrastructure development, technology transfer, and job creation. The role of FDI in driving growth highlights the potential for external capital to compensate for the limitations of oil rents and foster more diversified economic development. Similarly, both TB (0.0589, p< 0.05) and GCF (0.0893, p< 0.1) contribute positively to GDP growth. A favorable trade balance and strong domestic capital formation are vital for building a resilient economic foundation. These findings point to the importance of trade policies and domestic investment strategies that can support long-term growth by reducing dependency on volatile oil markets. While CPI shows a positive relationship with GDP growth (0.262, p< 0.05), this could indicate that moderate inflation is associated with periods of economic expansion. Inflation may be a byproduct of increased demand during growth periods, though it must be managed carefully to prevent it from becoming a destabilizing force. This highlights the need for careful inflation management policies to support sustainable growth. The negative and significant impact of the UN ( − 1.254 *, p< 0.01) further underscores the importance of addressing labor market inefficiencies. High unemployment rates hinder economic development by reducing productivity and consumption, making labor market reforms essential for achieving sustained growth. Efforts to lower unemployment are critical for ensuring that the benefits of economic expansion are more broadly shared and that productivity remains robust over the long term. PS also plays a significant role in supporting growth, with a positive coefficient of 0.0347 (p< 0.05). Political stability fosters a conducive environment for investment and economic development, highlighting the importance of governance and institutional strength in driving long-term economic performance. Stable political environments encourage investor confidence, which is crucial for sustaining growth in the face of global uncertainties. The robustness of the dynamic GMM model is supported by the diagnostic results presented in Table 15. The Arellano–Bond test for first-order autocorrelation (AR1) returns a statistically significant result (p= 0.0352), while the second-order autocorrelation test (AR2) is not significant (p= 0.1897). The absence of second-order autocorrelation confirms that the model is not biased by serial correlation, ensuring the reliability of the estimates. Additionally, the Sargan test for instrument validity reports a p-value of 0.2764, indicating that the instruments used in the GMM estimation are valid and not over-identified. These diagnostic results validate the model’s specification and confirm the robustness of the findings. Table 15. Autocorrelation and overidentification test results. Test Test Statistic p-Value First-Difference Arellano–Bond Test (AR1) −2.11 0.0352 Second-Difference Arellano–Bond Test (AR2) −1.31 0.1897 Sargan Test for Instrument Validity 23.76 0.2764 Overall, the dynamic GMM results offer valuable insights into the key drivers of GDP growth in the GCC. While oil rents remain important in the short term, the findings emphasize the need for diversification to mitigate the risks associated with resource dependency. The positive contributions of FDI, TB, and GCF highlight the importance of external and internal investments in driving long-term economic performance. At the same Economies 2024,12, 287 23 of 29 time, addressing challenges such as inflation, unemployment, and political stability will be crucial for sustaining economic growth and building resilience against future shocks. 5. Discussion This study provides critical insights into the relationship between market capitalization, oil rents, and socio-economic factors in shaping GDP growth in the Gulf Cooperation Council (GCC) countries. By employing a dynamic panel approach, we offer evidence supporting the need for economic diversification to sustain long-term growth. Our findings advance the literature on the resource curse and contribute to understanding the role of foreign direct investment (FDI) and gross capital formation (GCF) in resourcedependent economies. 5.1. Resource Curse and Economic Diversification Consistent with the resource curse hypothesis, our results demonstrate that while oil rents contribute positively to short-term GDP growth, their long-term sustainability is questionable. The diminishing effect of oil rents as additional variables are introduced into our models supports Hypothesis 2, which posited that oil rents constrain long-term economic expansion. This finding aligns with prior research (Sachs and Warner 2001; Fuinhas et al. 2015) that argues oil-rich economies often experiences underdevelopment of non-oil sectors, limiting innovation and making them vulnerable to external shocks. The addition of variables like foreign direct investment (FDI) and inflation further reveals the diminishing role of oil rents in driving GDP growth. As FDI flows increase, they contribute to economic diversification and the development of non-oil sectors, thereby reducing the relative importance of oil rents. Similarly, inflation can erode the purchasing power of oil revenues, further weakening their contribution to long-term growth. This supports the notion that oil rents, while significant in the short term, lose their influence as economies begin to diversify and rely on a broader base of investment and macroeconomic stability. The contribution of our study lies in refining the resource curse theory by demonstrating that FDI plays a critical role in mitigating its adverse effects. While oil rents are significant in the short term, the importance of external investments such as FDI for long-term growth suggests that attracting foreign capital is essential for diversification efforts. These results underscore the necessity for structural reforms aimed at reducing reliance on oil and promoting non-oil sectors, including technology, manufacturing, and services. Future studies could investigate the specific mechanisms through which FDI fosters innovation and structural transformation in oil-dependent economies. 5.2. Market Capitalization and Financial Market Development Although market capitalization exhibits a positive relationship with GDP growth, its significance is limited, particularly when compared to other variables such as trade balance and FDI. This partially supports Hypothesis 1, which suggested that while market capitalization can drive economic growth initially, its impact diminishes over time without structural reforms. The development of financial markets in the GCC remains crucial for funding diversification efforts, but our results suggest that financial market growth alone is insufficient without complementary policies focused on regulatory quality and governance. These findings add to the literature by highlighting that market capitalization must be supported by broader economic reforms to foster long-term sustainability. High-ranking studies on financial markets in resource-dependent economies (e.g., Kurronen 2015) also emphasize the need for sound regulatory frameworks to ensure stability and mitigate potential risks. Policymakers should therefore focus on improving regulatory oversight and fostering financial market resilience as part of their broader economic diversification strategies. 5.3. The Role of FDI and Gross Capital Formation (GCF) Our results indicate that FDI and GCF emerge as the most critical drivers of sustainable long-term growth. Hypothesis 3, which postulated that FDI and GCF play pivotal roles in Economies 2024,12, 287 24 of 29 economic growth, is strongly supported by our findings. FDI’s positive impact on GDP growth confirms its importance in providing external capital, technological transfer, and productivity improvements, echoing findings from Borensztein et al. (1998) and Alfaro et al. (2004). Moreover, the significant effect of GCF highlights the importance of domestic investment in physical infrastructure, machinery, and equipment, which lays the foundation for diversification. Policymakers in the GCC should not only attract FDI but also focus on stimulating domestic investment through favorable policies and incentives aimed at increasing Gross Capital Formation. Future research could explore the specific sectors where FDI and domestic investment yield the highest returns in terms of diversification and innovation. 5.4. Inflation and Unemployment Our findings show that inflation has a positive effect on GDP growth, particularly when it remains moderate, confirming the existence of an inflation-growth threshold, as suggested by Khan and Ssnhadji (2001). However, inflation must be carefully managed to avoid destabilizing economic growth. In contrast, unemployment exerts a significant negative effect on GDP, underscoring the urgent need for labor market reforms. High unemployment rates, particularly in the GCC, signal the underutilization of human capital, which is a key barrier to economic efficiency and diversification. This result reinforces the importance of aligning education with market needs and promoting labor market flexibility. Policymakers must address unemployment through job creation strategies that target both the youth and female workforce, which remain underrepresented in many GCC economies. By investing in human capital development, the GCC countries can create a more dynamic labor market that supports long-term economic stability. 5.5. Human Development and Long-Term Sustainability Although human development indicators (HDI) did not show immediate significance in the short-term analysis, the long-term benefits of investing in human capital cannot be overlooked. Our findings suggest that human capital development, through investments in education, healthcare, and research and development, will be crucial for sustained economic growth and diversification in the GCC. Human capital investments, particularly in education and healthcare, require time to build the necessary infrastructure, develop skilled labor, and improve institutional quality, which explains their limited impact on shortterm economic growth. However, in the long run, these investments enhance workforce productivity, promote innovation, and contribute to economic diversification, all of which are essential for sustained growth in resource-dependent economies like those of the GCC. This is consistent with research showing that human capital, measured through the HDI, plays a critical role in long-term productivity and innovation (Mabrouk and Abdulrahim 2021). Policymakers in GCC countries should continue to prioritize education and healthcare reforms, recognizing that these investments, while not immediately boosting GDP growth, are crucial for supporting future diversification efforts. Future studies should explore the long-term causal relationship between human capital development and economic diversification in resource-dependent economies. 5.6. Vulnerability to Global Shocks and the Performance of Oil Rents GCC countries are particularly vulnerable to global economic shocks due to their heavy reliance on oil rents for government revenues and foreign exchange earnings. During global crises such as the 2008 financial crisis and the COVID-19 pandemic, global demand for oil plummeted, leading to severe fiscal pressures for these economies. Reduced government spending followed, further depressing economic activity and highlighting the inherent vulnerability that comes with overdependence on oil exports. Despite efforts to diversify, many GCC economies still lack sufficient non-oil sectors to absorb the economic