This paper is an attempt to quantify some interaction effects among capital accumulation, population growth and sectoral technical change in economic development. We tried to find a balance in the difficult trade-off just mentioned. We built a simple dynamic general equilibrium model along neoclassical lines. It is an agricultural-nonagricultural two sector model of a closed economy. Due to its simplicity, causal chains are easily traced. But we do not pretend to capture a complete model of development and recognize that the parameters of the model may change over time, i.e., that there is structural change. Therefore no simulations are performed with the model. Instead, we tried to find parameter values for the model at various stages of the development of the Japanese and U.S. economies, and observe the model under widely different resource endowments between the economies and over time.