The document discusses the relationship between physical and human capital in economic growth, positing that economic development depends on their interaction rather than their individual levels. It emphasizes the importance of education and health as components of human capital and presents data analysis from 1990 and 2000 across 36 countries, questioning the evident U-shaped relationship previously suggested. The findings support a modified Solow growth model which incorporates both types of capital to better explain cross-country income differences and highlight the need for investment in human capital alongside physical capital.