Several economic-demographic models of a whole economy have been developed since Coale and Hoover first published their economic development in low income countries [1958].Coale and Hoover simulated an economy under alternative assumptions of high and low fertility. In their short-term model total product grew more slowly under high fertility than it did under low fertility. On the other hand in the long-run model although total product was higher under high fertility than under lon, fertility per capita income levels were considerably reduced