The Evolution of Population, Technology and Output

This paper extends Galor and Weil's (2000) unified growth model on the evolution of population, technology and output by replacing the parental utility function in which consumption and children are unrelated, with a more general specification in which some commodities are unrelated with children while the others are substitutes. Considering some leisure goods as the substitutes for children, it aims to explain the demographic transition from high to low fertility with the observed increase in the relative price of children to that of leisure goods along with Galor and Weil's quality-quantity mechanism based on the observed increase in the educational attainments. This modification leads to a conclusion that the demographic transition is a natural phenomenon in this environment when children become relatively more expensive than leisure goods, even for a given level of education and a given price of leisure goods. In addition, an increase in education and a decrease in the price of leisure goods contribute to the demographic transition.