Assumptions and methods: population, economic development, modelling and technical change.

The forecasts or assumptions of earlier writers are described, and the stance adopted in this bood is then explained. It is necessary to: 1) treat population as an exogenous variable, with some uncertainty over the time taken for Third World birth rates to drop towards their death rates; 2) attempt to provide for realistic levels of trade and aid in the world, and to include unemployment; 3) reject computer modelling; 4) note that continuing technological change is both desirable and necessary and there are unlikely to be any serious obstacles in its way. -K.Clayton