The dependent variable growth is the annual growth rate in real GDP per capita for
country i averaged over each 5-year interval t. The first set of explanatory variables
includes our state variables – the stock of human capital (proxied by the average
years of secondary education in the adult population) and the level of real per
capita GDP – both measured at the beginning of each 5-year interval. In the
neoclassical framework, the coefficient on the initial per capita GDP captures the
rate of convergence (i.e., the rate at which poor countries catch up with rich
countries) and is expected to be negative