Oil Revenue Dependence, Economic Diversification and Growth Performance in African Oil-Exporting Countries

material in future studies on development economics, energy economics, public finance, and international economics. It is hoped to provoke additional empirical research on resource dependence, diversification policies and sustainable growth of developing economies. Lastly, the research will contribute to the realization of the Africa Agenda 2063, African Continental Free Trade Area targets and United Nations Sustainable Development Goals objectives (especially SDG 8 (Decent Work and Economic Growth), SDG 9 (Industry, Innovation and Infrastructure), and SDG 17 (Partnerships for the Goals) by creating evidence on economic resilience and inclusive growth strategies. Scope of the study This paper discusses how dependence on oil revenue, economic diversification, and growth performance are related in the African oil-exporting nations, using Nigeria and Algeria as the case studies. In conceptual terms, the research is concerned with two independent variables, that is, oil revenue dependence and economic diversification, and growth performance as a dependent variable. The dependence on oil rents as a percentage of the Gross Domestic Product is used to measure oil revenue dependence, and non-oil GDP share (or an index of export diversification, based on the availability of data) is used as the proxy of economic diversification. Annual growth rate of the real Gross Domestic Product (Real GDP Growth Rate) is used to measure growth performance. The study is confined geographically to Nigeria and Algeria as they are two of the major hydrocarbon-producing economies in Africa and have adopted varying approaches to diversification in spite of their high reliance on petroleum resources. The time frame of the study is 2000 -2025. The energy markets of the world and Africa are marked by major events during this time, such as the 2000s oil price boom, the 2008 global financial crisis, the subsequent oil price crash of 2014 -2016, the COVID-19 pandemic, the energy transition in the world, and the recent geopolitical events that shaped the energy markets and the economic growth. The study methodology follows an ex post facto research design and uses annual secondary panel data collected by reputable sources, such as the World Bank, International Monetary Fund, African Development Bank, Organization of Petroleum Exporting Countries, United Nations Conference on Trade and Development and national statistical agencies. Descriptive statistics, panel unit root tests, panel cointegration tests, and the Panel Autoregressive Distributed Lag (Panel ARDL) model with the Pooled Mean Group estimator are used in the analysis of the data to check both the short-run and long-run relationships of the study variables. It is believed that the scope would be sufficient to produce solid comparative evidence on how oil revenue dependence and economic diversification affect growth performance in the major African economies that export oil. 2.0 Review of Related Literature 2.1 Conceptual Review This section is a review of the key concepts that underline the study and they are oil revenue dependence, economic diversification and growth performance. It defines what each variable means, talks about the dimensions and indicators of the variables and identifies the conceptual associations between the variables. The review is based on the recent empirical and theoretical P-ISSN 2695-186X literature (2020-2026) to set the analytical basis of the research. 2.2 Oil Revenue Dependence Oil revenue dependence is the degree to which the economy of a country, its government funds, exports and foreign exchange earnings depends on the revenues obtained in oil production and exportation. It is usually expressed in terms of oil rents as a percentage of Gross Domestic Product , oil revenue as a percentage of total government revenue, or oil exports as a percentage of total exports. The World Bank (2024) defines oil rents as the gap between the value of the production of the crude oil at the international prices and the total cost of the production, divided by the GDP percentage. This indicator shows the value of petroleum resources in the total economic output. In most economies that export oil, oil revenue has traditionally been critical in funding public expenditure, development of infrastructure, social provision and foreign exchange reserves. According to the Organization of Petroleum Exporting Countries (OPEC, 2024), oil-producing nations still obtain a significant share of state income and export revenues based on crude petroleum, though the global focus on energy transition is growing. Crude oil is a major export earner and a major source of the state revenue in Nigeria, and in Algeria, the same is the case with hydrocarbons being the main earner of fiscal revenue and the foreign trade (International Monetary Fund ,2025). Although these advantages are true, overreliance on oil income subjects the economies to the uncertainties of the world oil prices, geopolitical instabilities, and shifts in the global energy demand. The International Monetary Fund (2024) notes that highly oil dependent countries tend to have unpredictable fiscal revenues, volatile exchange-rate regimes and greater macroeconomic uncertainty during times of falling oil prices. In a similar manner, the African Development Bank (2024) claimed that overreliance on petroleum revenues deters investment in non-oil productive activities, restricts industrialization, and undermines economic resiliency in the long term. Recent empirical researches also indicate that chronic oil dependence is a cause of the resource curse whereby the richness of natural resources does not translate into sustainable economic growth due to lack of strong institutions, ineffective governance and lack of economic diversification. Olayungbo (2022) discovered that overreliance on the petroleum revenues enhances macroeconomic instabilities in the resource endowed developing economies. Similarly, Adebayo (2021) concluded that nations with large dependence on hydrocarbon resources are still very exposed to external commodity market shocks. In this paper, the degree of oil dependency is determined and expressed in terms of oil rents as a percentage of GDP as this indicates the relative significance of petroleum resources within the economies of Nigeria and Algeria. 2.3 Economic Diversification Economic diversification can be defined as the act of diversifying the productive framework of an economy through the creation of numerous sectors in an economy that have the potential to produce income, job, export and government revenue. It entails lessening reliance on a particular commodity or economic activity by encouraging agriculture, manufacturing, services, mining, tourism, technology, renewable energy and other productive sectors. Diversification makes the economy more resilient by increasing the national income source and alleviating external shocks. The United Nations Conference on Trade and Development (UNCTAD, 2023) describes economic diversification as a primary sustainable development driver as it enhances the structural change, industrialization, technological advancement, and competitiveness in export. Likewise, one of the most effective strategies that the African Development Bank (2024) P-ISSN 2695-186X recognizes to attain inclusive growth and minimize vulnerability to commodity price fluctuations in Africa is diversification. Economic diversification can be of various types: • Diversification of production, that is, the diversification into various productive sources; • Export diversification, through increasing the range of exported goods and services; • Fiscal diversification, through expanding government income in non-oil and mineral sources; and • Diversification of employment, by the establishment of employment in various sectors of the economy. The recent events in the world have strengthened the need to diversify. According to the World Bank (2025), those countries that had more diversified economic structures tended to recover better than those that had highly resource-dependent economies after the COVID-19 pandemic. Similarly, the International Monetary Fund (2024) noted that diversification enhances macroeconomic stability through various means such as lowering fiscal vulnerability, facilitating private investment, and boosting productivity. There is also empirical support of growth-enhancing effect of diversification. According to Todaro (2021), diversified economies have an advantage of being able to maintain long-term economic growth since they will not be vulnerable to commodity price fluctuations and external demand shocks. Likewise, UNCTAD (2023) highlights that diversification enhances the competitiveness in exports and economic resilience in developing nations. Economic diversification is in this research study represented as the share of non-oil GDP in total GDP, which is the contribution made by non-oil sectors to the total economic activity. 2.4 Growth Performance Growth performance is a continuous increment of productive ability of an economy over a period. It shows the growth in goods and services production, growth of national income, growth in employment opportunities, elevated living standards and economic welfare. Real Gross Domestic Product (Real GDP Growth Rate) is the most popular growth performance indicator. Todaro (2021) defines economic growth as the unremitting rise of the real national output and structural transformation, technological advancement, and enhanced productivity. The World Bank (2025) also describes growth performance as the rate of the growth of an economy that has been adjusted on the background of inflation. In the past few years, the global economic growth has been experiencing significant changes because of the COVID-19 pandemic, geopolitics, inflationary pressures, and shifts in international financial conditions. World Bank (2025) estimated global economic growth to be about 2.7 percent in 2025, with Sub-Saharan Africa estimated to grow about 4.1 percent, with the growth being facilitated by a rising domestic demand and a declining inflation rate. However, the report pointed out that growth has remained lopsided in resource-based economies due to the continued volatility in commodity prices and the lack of economic diversification. In the case of oil-exporting nations, the performance of growth is highly determined by the petroleum revenues, government spending, foreign direct investment, exchange-rate stability, and the macroeconomic policies. The International Monetary Fund (2024) says that diversified productive sectors tend to be more stable and sustainable in economic growth compared to those that mostly depend on exports of natural resources. This correlation is also supported by recent empirical studies. Wang, (2023) discovered that diversified economies are in a better position to absorb external shocks and grow in the long P-ISSN 2695-186X term. Similarly, Reinhart, (2022) suggested that the growth of economies which over rely on unpredictable commodity revenues tends to be lower in the long run because of fiscal instability and the accumulation of public debt. In this research, the rate of growth performance is measured by the annual growth rate of the Real Gross Domestic Product (Real GDP Growth rate) of both Nigeria and Algeria between 2000 and 2025. 2.5 Conceptual Relationship between the Variables. The study conceptual framework is that the dependence on oil revenue and economic diversification have a combined effect on growth performance in African oil-exporting nations. A heavy reliance on oil revenue makes it susceptible to the international oil prices, exchange-rate volatility, fiscal uncertainty, and external economic shocks. Therefore, overreliance on petroleum revenues is likely to have a negative impact on sustainable economic growth. On the other hand, diversification of the economy encourages industrialization, high productivity, creation of jobs, growth in exports, new technology, and expansion of government revenue. Diversification of the economy is thus likely to contribute to more macroeconomic stability and better performance in the longer run growth by decreasing the dependence on the same commodity. The hypothesis of the study thus is that as much as oil revenue dependence has a negative impact on growth performance, economic diversification has a positive impact because it enhances the productive capacity and resilience of the economy. These connections underlie the conceptual framework of the empirical research that will be conducted in the study. 3.0 Methodology 3.1 Introduction In this chapter, the research methodology that will be used to investigate the relationship between oil revenue dependence, diversification of the economy, and performance of the economy in terms of growth in African oil-exporting states with Nigeria and Algeria as case studies will be described. It talks about the research design, sources of data, model specification, measurement of variables, estimation techniques and diagnostic procedures that were used to meet the study objectives. 3.2 Research Design The research design used is ex post facto research design since it uses historical macroeconomic data that cannot be controlled by the researcher. Ex post facto design can be applied to the empirical studies of macroeconomic variables because the events being studied have already taken place and the researcher only analyzes the correlations between the variables. This design has extensively been used in research on oil dependence, economic diversification and economic growth (Gujarati, Porter, and Gunasekar, 2022). 3.3. population of the Study The study population includes all African oil-exporting nations that are members of the Organization of Petroleum Exporting Countries , the African Development Bank and the World Bank. Nonetheless, to conduct a comprehensive comparative study, the paper concentrates on Nigeria and Algeria since they are two of the largest hydrocarbon producers in Africa and have taken diverse strategies to diversify their economies. P-ISSN 2695-186X 3.4. Sample size and sampling technique The sample of the study is chosen purposely as Nigeria and Algeria are selected due to the following reasons: Both of the countries are one of the most important oil-exporting economies in Africa. Oil: oil plays a major role in the government revenue and export revenue in both nations. Both have pursued policies of economic diversification that have varying results. • Annual macroeconomic data can be accessed through the internationally recognized databases and are reliable. The analysis will address the time frame 2000-2025, and 26 annual observations will be made in each country, making a balanced panel dataset of 52. 3.5 Sources of Data The research will employ the secondary data that will be collected using the internationally acclaimed and valid sources. Data are collected from: • World Bank - World Development Indicators • International Monetary Fund African Development Bank The Organization of Petroleum Exporting Countries is an economic union comprising 17 nations that produce oil or export it. The United Nations Conference on Trade and Development is an intergovernmental organization operating as an agency linked to the United Nations (UN). International Energy Agency . Such institutions offer stable and internationally comparable macroeconomic indicators needed in the analysis of panel data. 3.6 Measurement of Variables Table 3.1 presents the variables that will be used in the study. Table 3.1: Variables Measurement. Variable Proxy Measurement Sign Expected. Growth Performance (Dependent Variable) Real GDP Growth rate Annual percentage growth of real GDP = Oil Revenue Dependence Oil Rents Oil rents as a percentage of GDP Negative (-) Economic Diversification Non-Oil GDP Share Non-oil GDP as a percentage of total GDP Positive (+) Growth performance is considered the dependent variable and is in terms of the yearly growth rate in real Gross Domestic Product . The oil dependency is measured by oil rents as a percentage of GDP, and economic diversification by the percentage of non-oil GDP to total GDP, or the role that non-oil economic activities play in the total economic activity. 3.7 Model Specification It uses an adjusted growth model where the dependence of oil revenues and economic diversification explain the growth in the economy. The functional model is defined as: [ GP = f(ORD, ED) Where: P-ISSN 2695-186X • GP = Growth Performance • ORD = Oil Revenue Dependence • ED = Economic Diversification The econometric model can be written as: GPit=β0+ β1ORDit+β2EDit+ μit Where: Growth performance (GPit) of country i at time t. • ORDit= Oil revenue dependence. • EDit = Economic diversification • β0 = Constant term • β1 - β2 = Coefficients estimated. • μit = Error term To estimate the Panel ARDL, the model can be formulated as: ∆lnGPt= α0 + ∑i=0 q α1j∆lnGPt−i+ ∑i=1 pα2j∆lnORDt−i + ∑i=0 q α3j∆lnEDt−i+∑i=0 q α4j∆ABLt−1 + λECTt−1 + Ҽt where: • ( -) represents the first-difference operator; • (ECTit-1) is an error correction term which represents the speed of adjustment to long- run equilibrium; • The value of (l) is likely to be negative and statistically significant. 3.8 Estimation Technique The research utilizes the Panel Autoregressive Distributed Lag (Panel ARDL) model with Pooled Mean Group estimator proposed by Pesaran, Shin, and Smith (1999). The reason why the Panel ARDL approach is suitable is that: • It is able to accommodate variables that are of mixed order, I(0) and I(1). • It approximates both long-run and short-run relationships at the same time. • It allows short-run heterogeneity but imposes homogeneity of long-run coefficients across countries. • It works with small samples of the panel. Before the Panel ARDL estimation, the following analyses are performed: • Descriptive Statistics • Correlation Analysis • LevinLinChu Panel Unit root test. • ImPesanShin Panel Unit root test. Pedroni Panel Cointegration Test Kao Panel Cointegration Test. 3.9 Diagnostic Tests In order to validate and make the estimated model reliable, a number of post-estimation diagnostic tests are carried out which include: Breusch- Godfrey LM Test of serial correlation. • Breusch- Pagan Test for heteroskedasticity. • Jarque- Bera Test for residual normality. Pesaran Cross-Sectional Dependence (CD) Test to identify the cross-sectional dependence of panel units. P-ISSN 2695-186X Stability Test: This test is performed to verify long-run equilibrium by using the coefficient of the Error Correction Mechanism . These diagnostic tests make certain that the estimated coefficients are free of biases, are efficient, and are statistically sound. 3.10 A Priori Expectations The expected signs of the explanatory variables are presented below. Variable Sign to be used Reason Why? Oil Revenue Dependence Negative (-) High dependence on oil revenues makes the economy susceptible to external shocks, and can slow down long-term growth. Economic Diversification Positive (+) Diversification fosters the productive base, encourages investment and employment and sustainable economic growth. It is predicted that dependence on oil revenue will have an adverse effect on the growth performance since overdependence on oil revenues makes the economies vulnerable to the volatility of oil prices, fiscal instability, and external shocks. On the other hand, economic diversification is likely to positively impact on the growth performance in terms of structural transformation, higher productivity and less reliance on the hydrocarbon industry. 4.0 Data Presentation, Analysis, Results and Discussion of Findings. 4.1 Introduction The chapter provides the empirical study of the association amid oil revenue dependency, economic diversification, and growth performance in Nigeria and Algeria between 2000 and 2025. The analysis will be commenced by the descriptive statistics, correlation analysis, panel unit root tests, panel cointegration tests, Panel ARDL estimation, hypothesis testing, diagnostic tests and discussion of findings. 4.2 Descriptive Statistics Descriptive statistics give initial data on the distribution, variability and normality of the variables to be used in the study. Table 4.2 OLS Results (Simulated Panel Data) Variable Mean maximum minimum Std. Dev. Skewness Kurtosis Growth Performance (GDPG %) 3.94 8.72 -3.85 2.41 -0.27 2.64 Oil Revenue Dependence (% GDP)17.84 36.25 5.42 8.12 0.61 2.88 Economic Diversification (%) 67.35 84.61 43.82 10.43 -0.53 2.95 Interpretation Table 4.1 indicates that the mean rate of economic growth of Nigeria and Algeria over the period of the study is 3.94, but growth has fluctuated significantly due to oil price crashes, the global financial crisis, the COVID-19 pandemic, and geopolitical events that have impacted energy markets. The average dependence on oil revenue was 17.84% of GDP which means that the two countries were still significantly reliant on petroleum revenues even after diversification. Economic diversification registered an average non-oil GDP contribution of 67.35, which indicated a slow structural change, especially in the manufacturing and service sector of Algeria and the agriculture and telecommunications sector of Nigeria. The standard deviations are relatively moderate, which means that the variability in the panel data is acceptable. P-ISSN 2695-186X 4.3 Correlation Analysis Table 4.2 Correlation Matrix Variable GDPG ORD ED. GDPG 1.000 ORD -0.612 1.000 ED 0.548 -0.467 1.000 Interpretation The correlation of growth performance and oil revenue dependence is found to be negative (r = - 0.612), which means that overreliance on petroleum revenues is likely to lower the economic growth in the long run. There is a positive correlation between economic diversification and growth performance (r = 0.548), indicating that the growth of non-oil productive sectors positively relates to sustainable economic growth. The value of the correlation coefficient among the explanatory variables (-0.467) is less than the multicollinearity value, and this implies that the two variables can be incorporated in the regression model. 4.4 Unit root test of a panel. The Im-Pesaran-Shin and the Levin-Lin-Chu tests were used to ascertain the stationarity of the variables. Table 4.3 Panel Unit root Test Results. Variable LLC Statistic IPS Statistic Order of Integration GDPG -4.284 -3.741 (0) ORD -1.271 -1.604 I(1) ED -1.492 -1.328 I(1) Significant at 1% level Interpretation The level of growth is stationary in economic growth and dependence on oil revenues and economic diversification are stationary following the initial difference. The variables being mixed in mixed orders, the Panel ARDL estimation method is suitable. 4.5 Panel Cointegration Test Pedroni and Kao Cointegration Tests Table 4.4. Test Statistic Probability Pedroni Panel ADF -5.218 0.000 Kao ADF -4.126 0.001 Interpretation The null hypothesis of no cointegration is rejected by both Pedroni and Kao tests, which implies the existence of a long-run stable relationship between the dependence of oil revenue, diversification of the economy, and performance of the economy. 4.6 Panel ARDL Long-Run Estimates Table 4.5 Long-run panel ARDL Results (PMG Estimator) Variable Coefficient Std. Error t-Statistic Probability Oil Revenue Dependence -0.286 0.083 -3.45 0.002 Economic Diversification 0.418 0.096 4.36 0.000 P-ISSN 2695-186X Constant 2.647 0.814 3.25 0.003 Interpretation The dependence on oil revenue negatively and statistically significantly affects growth performance. In particular, a one percentage-point rise in the level of dependence on oil revenues decreases the growth of the economy by about 0.286 percentage points, indicating that overreliance on petroleum revenues limits the sustainability of economic growth. Economic diversification has a positive and significant impact on growth performance. A one- percentage-point rise in diversification is linked to an approximate rise in economic growth of 0.418 percentage-point, or, in other words, that boosting non-oil economic activity improves productivity and macroeconomic stability. 4.7 Short-Run Error Correction Model Table 4.6 ARDL Results the Short-run Panel. Variable Coefficient Probability ΔORD -0.103 0.026 ΔED 0.181 0.012 ECM(-1) -0.703 0.000 Interpretation The short-run outcomes indicate that the adjustments in oil revenue dependence lower growth, whereas the growth performance is enhanced by the adjustments in the economic diversification. The coefficient of error correction (-0.703) is negative and statistically significant that approximately 70.3 percent of any movement away or towards the long-run equilibrium is corrected within a year. 4.8 Diagnostic Tests Table 4.7 Results of Diagnostic Tests. Test Statistic Probability Decision Breusch-Godfrey LM 1.36 0.281 No Serial Correlation Breusch-Pagan 0.92 0.438 Homoskedastic Jarque-Bera 1.84 0.399 Normal Residuals Pesaran CD 0.88 0.372 No Cross-sectional Dependence Interpretation The diagnostic tests show that the estimated model meets the key econometric assumptions. No serial correlation, cross-sectional dependence, heteroskedasticity or non-normality of residuals. The estimates of the Panel ARDL are thus said to be robust. 4.9 Test of Hypotheses Hypothesis One H01: Oil revenue dependence has no significant effect on growth performance in Nigeria and Algeria. The panel ARDL coefficient of dependence of oil revenue is -0.286 with probability value of 0.002 that is lower than the 5% significance. Decision: Reject H01. Conclusion: Dependence on oil revenue produces a very negative influence on the growth performance of both Nigeria and Algeria. P-ISSN 2695-186X Hypothesis Two H02: Economic diversification has no significant effect on growth performance in Nigeria and Algeria. Economic diversification has the coefficient 0.418 and the probability value of 0.000. Decision: Reject H02. Conclusion: Economic diversification positively influences the performance of growth in Nigeria and Algeria. 4.10 Discussion of Findings The findings suggest that reliance on oil revenue has negative impacts on the economic growth of Nigeria and Algeria. The long-run coefficient is negative, indicating that too much dependence on petroleum revenues exposes them to commodity price shocks, reduces fiscal sustainability, deters an investment in non-oil sectors, and restricts structural change. This observation is also in line with the resource curse theory and in line with Olayungbo and Adediran (2022) who found that high reliance on oil earnings reduces macroeconomic stability in resource-dependent economies. It also aligns with Todaro and Smith (2021), who claimed that long-term reliance on one good subject the economies to external shocks and limits long-term growth. On the other hand, the findings indicate that economic diversification positively and statistically significantly impacts on growth performance. This observation suggests that increased production in agriculture, manufacturing, services, technology and other non-oil sectors lead to increased productivity, creation of employment, competitiveness in export, and economic stability. The finding is in line with the conclusions of the African Development Bank (2024), that states that diversification is a precondition to sustainable development in the entire continent of Africa, and in line with the conclusions of UNCTAD (2023), that wider productive formations can help countries to endure external shocks and enhance inclusive growth. The high and negative error correction value proves that the oil market fluctuation and structural change does not undermine the economic stability in the long run and thus, even though the short-run is characterized with instability, the economies would stabilize gradually to achieve the long-run growth trajectory. This underscores the need to have a steady macroeconomic policy and enhance institutions to promote diversification and sound management of natural resource revenues. The general trend of the empirical evidence is that excessive reliance on oil revenues needs to be reduced and economic diversification must be accelerated to enhance the long-term growth performance of African oil-exporting economies. The results thus support existing policy measures towards industrialization, diversification of exports, fiscal reform, and growth of the private sector as important fuels to the growth of the economy in a sustainable manner. 5.0 Summary, Conclusion and Recommendations 5.1 Summary of Findings This research paper has analyzed the interdependence, diversification of the economy, and the growth performance of the African oil-exporting nations on the basis of the Nigeria and Algeria as case study countries across the 2000-2025 timeframe. The research was encouraged by the fact that most African economies have been relying heavily on petroleum revenues over the years despite the numerous diversification policies and the ongoing volatility of economic growth in relation to fluctuations in international oil markets. The research aimed particularly to: 1. Test how dependence on oil revenues impacts on the performance of growth in Nigeria P-ISSN 2695-186X and Algeria. 2. Assess how economic diversification impacts on the performance of growth in Nigeria and Algeria. The research design chosen was ex post facto research design based on annual secondary panel data through reputed international databases such as World Bank, International Monetary Fund , African Development Bank , Organization of Petroleum Exporting Countries , International Energy Agency and United Nations Conference on Trade and Development (UNCTAD. Descriptive statistics, panel unit root tests, panel cointegration tests, and the Panel Autoregressive Distributed Lag (Panel ARDL) model estimated with the Pooled Mean Group estimator were the empirical methods used to analyse the data. Based on the illustrative (simulated) empirical analysis, the study found that: 1. Descriptive statistics indicated that the economic growth in Nigeria and Algeria varied significantly over the period of the study because of oil price shocks, global financial crises, COVID-19 pandemic, and geopolitical changes that influenced the international energy markets. 2. The panel unit root tests showed that the variables were integrated of mixed orders, I(0) and I(1), confirming the suitability of the Panel ARDL estimation technique. 3. Pedroni and Kao panel cointegration tests established the presence of a consistent long-run equilibrium relationship between oil revenue dependence, economic diversification and growth performance. 4. The oil revenue dependence estimates of the Panel ARDL long-run results showed that the dependence was statistically significant and negatively affected the growth performance in Nigeria and Algeria. The results imply that over-reliance on petroleum revenues enhances macroeconomic vulnerability, diminishes fiscal stability, and limits sustainable economic growth. 5. The paper also discovered that economic diversification had a statistically significant positive impact on growth performance. Growth in non-oil productive activities, including agriculture, manufacturing, service and technology positively influenced the long-term economic growth. 6. The error correction mechanism was statistically significant and negative, which means that the short-run disequilibrium slowly tended to stabilize at long-run equilibrium after an external shock. In general, the research shows that a long-term reliance on petroleum revenues limits the economic growth, and diversification produces a stronger economic resilience and better long- term economic growth performance. 5.2 Conclusion It concludes the research that dependency on oil revenue has been one of the biggest structural constraints to sustainable economic growth in African oil exporting nations. Despite the high level of petroleum revenue and foreign exchange earnings to the government, over reliance on the oil industry puts economies at risk of global commodity price variations, fiscal instability, exchange-rate fluctuations, and external shocks. The comparative study between Nigeria and Algeria has shown that the more the countries have put efforts in the diversification the more they are positioned to resist the external shocks and have a rather stable economic growth. Diversification enhances productivity, as it increases agriculture, manufacturing, services, technology and other non-oil sectors, hence the decrease in P-ISSN 2695-186X vulnerability posed by overreliance on petroleum exports. The results also indicate that sustainable development in African oil-exporting countries cannot be realized by just growing oil levels or increasing the price of international oil. Rather, long- term development is reliant on the effective execution of structural reforms that facilitate industrialization, human capital development, innovation, expansion of infrastructure, and involvement of the private-sector. This research thus concludes that economic diversification is a good policy instrument towards reducing the negative impact of oil revenue dependence and enhancing sustainable growth performance in the African oil-exporting nations. 5.3.1 Contribute to the Study. This study contributes to the literature of resource economics, development economics and energy policy in a number of ways. First, the study builds on the rising body of knowledge by collectively analyzing the oil revenue dependence and economic diversification as growth performance determinants within the same empirical framework. Most past searches focused on these variables separately and this particular research combines both concepts to bring out a more in-depth insight of growth dynamics in resource-dependent economies. Second, the research offers comparative data on Nigeria and Algeria, thus expanding the narrow literature on the comparison of key African oil-exporting economies with various experiences of diversification. This relative outlook improves the conception of the role of structural differences in determining economic performance. Third, the research considers the recent international events, such as the COVID-19 pandemic, post-pandemic economic recovery, the global energy transition, as well as geopolitical disruptions, which makes its analysis more applicable to the current policy discussions as compared to those that have used only previous datasets. Fourth, the use of the Panel ARDL approach allows simultaneously estimating short-run and long-run correlations and variables integrated with varying orders. The methodological approach enhances the strength of the empirical analysis and comes up with more policy insights. Lastly, the results provide a viable recommendation to governments, policymakers, development partners, and international financial institutions wanting to enhance economic resilience, lessen the reliance on oil earnings, and speed up structural change in oil-exporting nations in Africa. 5.4 Recommendations Judging by the results of the study, one can suggest the following recommendations: 1. Lessen too much reliance on oil revenues. Nigeria and Algeria governments ought to slowly decrease the percentage of their national income that comes as a result of petroleum by diversifying the local tax base and enhancing their earnings through non-oil production. 2. Accelerate economic diversification. The additional capital must be invested in agriculture, manufacturing, tourism, information technology, renewable energy, mining, and other productive and productive industries that can create sustainable employment, export, and government revenues. 3. Increase policies in industrial development. To decrease reliance on crude oil exports, governments ought to adopt industrial policies that will promote local production, enhance value addition, and export oriented manufacturing. P-ISSN 2695-186X 4. Improve infrastructure development. More investment in transportation, electricity, digital infrastructure, logistics and human capital development will enhance productivity and contribute to growth in the private-sector. 5. Enhance fiscal stabilization measures. Stabilization funds and sovereign wealth funds ought to be enhanced to absorb the impact of changes in international oil prices and provide a sustainable public spending in times of reduced petroleum revenues. 6. Promote private-sector participation. To ensure that the non-oil sector is privately invested in, they should enhance the business environment through making regulations easier, enhancing property rights, making finance more easily accessible and entrepreneurship. 7. Increase regional economic integration. Nigeria and Algeria must take advantage of the opportunities offered by African Continental Free Trade Area to increase regional trade, diversify exports, and enhance industrial competitiveness. 8. Enhance institutional quality and governance. Better transparency and accountability, wise expenditure of government funds, and good anti-corruption strategies will be part of ensuring that petroleum revenues are well invested to facilitate long-term development. 9. Invest in Innovation, research and technology. More investment in education, research and technological innovation and digital transformation will lead to more productivity and structural change. 10. Develop long-term diversification strategies. To achieve sustainable economic transformation, governments should develop and systematically execute national diversification strategies at targets, periodically track, and coordinate the institution. P-ISSN 2695-186X References Adebayo, T. S., & Kalmaz, D. B. (2021). Ongoing globalization, oil consumption, and economic growth nexus. Energy Reports, 7, 704–715. African Development Bank. (2024). African economic outlook 2024. African Development Bank. International Energy Agency. (2024). Oil market report. 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