The popularisation of higher education is crucial for achieving the UN's Sustainable Development Goal 4 (inclusive and equitable quality education). However, its impact on economic growth and poverty alleviation remains under-explored. This study addresses this gap by examining the relationship between higher education popularisation (measured by the proportion of the population with higher education and adult education levels) and economic growth (GDP) and poverty rates across 38 countries. The study hypothesizes that higher education popularisation will positively impact GDP growth and poverty reduction. The research questions explore the effect of higher education on GDP growth, the effect of adult education on GDP growth, the impact of higher education on poverty reduction, and the relationship between adult education and poverty. The study uses panel data from 1995-2021, sourced from the OECD and World Bank databases, applying OLS and quantile regression methods to analyse the data and address the research gap of limited studies simultaneously exploring the effects of higher education popularisation on both economic growth and poverty alleviation. This study contributes by offering a broad-scale analysis of this important relationship, considering both the overall level of higher education development and the degree of its popularisation.

Existing literature highlights the significant contribution of higher education to economic growth by increasing human capital and productivity. Studies have shown a positive correlation between higher education expansion and economic growth, particularly in the advancement of science and technology. However, the effect may become marginal with continuous expansion. Research also emphasizes the role of higher education in poverty alleviation, although it's not a panacea. A lack of education is a significant factor in poverty, and educational inequality contributes to overall inequality. While the expansion of higher education offers opportunities for social mobility, ensuring the quality and relevance of education is crucial for maximizing its impact. This study builds upon this existing research by providing a more comprehensive analysis using panel data and considering both the overall level and popularisation of higher education, addressing the gap in simultaneous investigation of its effects on economic growth and poverty alleviation. Theoretical underpinnings are drawn from Solow's growth theory, which emphasizes technological progress as key to sustainable economic development and the human capital theory, which highlights education’s contribution to economic growth by improving labor productivity.

This study employed OLS (Ordinary Least Squares) regression and quantile regression to analyze panel data from 38 OECD countries between 1995 and 2021. The data, obtained from the OECD and World Bank databases, included GDP as a measure of economic development, the poverty line (proportion of people living below $2.15 a day) as a measure of economic equity, and two independent variables representing higher education popularisation: the proportion of 25-64-year-olds who completed higher education (reflecting the overall development level) and the proportion of 25-34-year-olds with higher education relative to their peers (reflecting the popularisation degree). The study adapted the Mankiw-Romer-Weil model, incorporating higher education development and popularisation as independent variables to predict GDP and poverty rates. OLS regression was used to test the overall effect, while quantile regression was employed to analyze the impact across different percentiles of economic development and poverty, allowing the researchers to observe how the effect varied across different levels of development. The study applied various statistical tests, such as F-tests, t-tests, and correlation analysis, to determine the statistical significance of relationships. Heteroscedasticity was addressed using robust standard error regression. Variance decomposition and Pearson correlation coefficients were calculated to understand the relative contributions of the independent variables and their relationships with the dependent variables.

The OLS regression results showed that the proportion of 25-64-year-olds with higher education had a significantly positive impact on GDP growth (coefficient 1.553, p<0.01), while the proportion of 25-34-year-olds with higher education (representing popularisation) had a significantly negative impact (coefficient -0.813, p<0.01). This suggests that while a higher overall level of higher education contributes positively to economic growth, over-expansion or oversupply of graduates in the younger age group may lead to negative consequences. Variance decomposition indicated that the proportion of 25-34-year-olds explained 50.74% of GDP change, and the proportion of 25-64-year-olds explained 49.26%. Regarding poverty, only the popularisation variable (25-34-year-olds) showed a significant negative impact (coefficient -0.048, p<0.01), suggesting higher education popularisation is effective in reducing poverty but that overall higher education attainment does not have an impact. Quantile regression analysis revealed that the impact of both variables on GDP varied across different quantiles of economic development, demonstrating a positive impact in early stages and a negative impact in later stages, highlighting the importance of balanced development. Similarly, the impact of higher education popularisation on poverty reduction was contingent on the level of development, with positive effects seen in certain quantiles. The correlation analysis showed a strong positive correlation between the two higher education variables, while a significant positive correlation was observed between the higher education popularisation variable and GDP, and a significant negative correlation between higher education popularisation and poverty.

The findings suggest a nuanced relationship between higher education popularisation and economic growth and poverty alleviation. While higher education contributes positively to GDP growth, particularly among the working-age population, the rapid expansion without sufficient demand can lead to negative consequences. This underlines the need for strategic planning and investment in higher education, ensuring alignment with labor market demands. The findings relating to poverty reduction indicate that increased access to higher education, particularly among younger populations, can play a role in reducing poverty. However, the effectiveness of this strategy varies across countries at different development stages. The study suggests a potential overcapacity in higher education systems in some advanced countries, which may lead to wasted resources and unemployment among highly-educated individuals. This calls for policymakers to consider the potential trade-offs between quantity and quality of higher education, promoting investment in quality over mere expansion. Furthermore, equitable distribution of educational resources and opportunities across different socioeconomic strata is crucial for maximizing the impact of higher education on poverty reduction.

This study's findings underscore the complex and multifaceted impact of higher education popularisation on economic growth and poverty alleviation. While increased higher education attainment among the working-age population is associated with greater GDP growth, the level of popularization needs to be carefully considered to avoid negative consequences. The positive impact on poverty reduction is stronger through enhanced access among younger populations. This highlights the importance of strategic planning and investment in higher education that considers both quantity and quality, alongside equitable resource allocation. Future research could investigate causal relationships using more advanced econometric techniques and incorporate qualitative data to explore local contexts. Further study into different educational sectors, regional variations, and the long-term impacts of higher education popularisation would provide even more comprehensive insights.

This study has several limitations. The use of panel data from 38 OECD countries limits the generalizability of the findings to non-OECD countries or regions with vastly different socio-economic contexts. The study relied on aggregate data, potentially obscuring variations within countries. The cross-sectional nature of the analysis does not allow definitive causal inferences to be drawn, and future studies should employ more advanced techniques to establish causality. Additionally, the study did not incorporate qualitative data to explore diverse cultural and historical factors that may influence the relationship between higher education and economic outcomes. Finally, incorporating other variables (e.g., government policies, technological advancements, global economic conditions) could offer a more comprehensive understanding of the complex interplay of factors influencing economic growth and poverty reduction.