Possibly the most widely investigated adverse impact of population on economic growth is based on the hypothesized negative effect of population on the availability of savings for capital formation. Even though diminishing returns to land and natural resources due to increased population size has also constituted a long-run concern of economists, the magnitude of this impact has historically been attenuated largely by improving or augmenting the stock of land through capital formation. If population growth exerts a quantitatively significant detrimental effect on the rate of capital formation, then the diminishing-returns argument will hold with greater force. Similarly, economic development may be explained in part by increases in labor productivity which are due to technical progress; again, if embodied technical change plays a role, then the rate of capital formation-and population's relation to it-may be critical. The present paper examines several connections between population growth and the supply of savings for investment. Attention is centered on the relationship between family size and the rate of household saving.