An Empirical Comparative Analysis of GDP, GDP per Capita, Purchasing Power Parity and Human Development

This study presents a cross-sectional empirical comparison of the 50 economies ranked highest by GDP per capita at purchasing power parity (PPP) for 2026. Using IMF World Economic Outlook (April 2026) macroeconomic estimates as presented in IMF-based international tables, the study integrates nominal GDP, nominal GDP per capita, GDP growth, GDP per capita PPP and population, and links these indicators to the latest comparable Human Development Index (HDI) values reported by UNDP for 2023. Descriptive statistics, Pearson correlations, multiple regression and one-way ANOVA are applied. GDP per capita PPP ranges from US$53,769 to US$195,372, with a mean of US$86,186.54 and a coefficient of variation of approximately 36.76%. Population is strongly associated with total GDP (r=.965, p<.001), whereas total GDP is not significantly associated with nominal GDP per capita (r=.050, p=.729). GDP per capita PPP is not significantly correlated with HDI in this restricted high-PPP sample (r=.144, p=.362). In the multivariate HDI model, GDP per capita PPP has a positive but nonsignificant coefficient at the 5% level (B=.0321, p=.086), while growth and population show statistically significant associations. The findings demonstrate that economic scale, purchasing-power-adjusted prosperity and human development are complementary rather than interchangeable dimensions.