Jointly determined saving and fertility behaviour: theory, and estimates for Germany, Italy, UK and USA.

This study uses new theories of capital accumulation and fertility in a comparative framework to test predictions with time-series data for Germany, Italy, the UK, and the US. The exogenous-fertility model is based on models of Barro and Becker. The endogenous-fertility models are based on models of Veall and Nishimura and Zhang. It is assumed that life cycle periods are youth, middle age, and old age. Several theoretical frameworks are tested with endogenous and exogenous fertility and altruism and nonaltruism. Data are obtained during 1950-90. Dependent variables are the total lifetime fertility rate and real per capita household savings. Explanatory variables include social security, the real social security deficit per capita, the real rate of interest, the real per capita disposable income, the average male real wage rate, the average female real wage rate, and the real child benefit rate. The explanatory variables are individually graphed to show differences by country over time. Findings suggest that fertility is endogenous in a nonaltruistic model. The only model not rejected by the data was the model in which fertility and intergenerational transfers were explained by nonaltruistic concerns. Fertility was positively affected by the male wage rate in all countries. Fertility was negatively affected by the female wage rate in all countries. Disposable income was insignificant in the UK and Germany and positive and significant in Italy and the US. The interest rate was significant in only 1 model. Child benefits had a positive and significant effect on fertility in the UK. In savings models, disposable income was significant and positive, and child benefits and wage rates were insignificant. Social security coverage had a negative effect on fertility and a positive effect on savings, except in Germany. Findings indicate that saving and fertility are jointly determined.