Hence, growth issues had to wait until the late 1980s to be revived by the availability of internationally comparable data on income and price levels (Summers and Heston, 1988), and by the rise of another approach to the study of economic growth – the endogenous growth models - pioneered by Romer (1986) and Lucas (1988), where the long run growth rate of productivity emerged endogenously from the [...] In other words, the cross-country differences in the steady states of income per capita emerge because of differences in the accumulation of human and physical capital, and in the growth rate of population. [...] The s. variable is measured as the average k output share of investment over the period, and the growth rate of population, n, is also the average value observed for the 1960-1985 period. [...] The other variables, measured as averages over each period, are the log of the total fertility rate, the ratio of government consumption to GDP (exclusive of defence and education), and the democracy index. [...] They regress growth on initial levels of stocks of physical and human capital (men and women simultaneously) and a set of variables that reflect the current political context like the black market premium, life expectancy, the number of revolutions per year and the ratio of government consumption and investment to GDP.