The theory of population growth cycles.

Four theoretical types of population growth cycles are presented. Growth cycles from lower death rates in combination with stationary birth rates seem to have characterized preindustrial societies. A growth cycle resulting from a lag of the birth rate behind the death rate while both are declining appears to have accompanied industrialization. Future growth cycles in industrialized societies will probably depend upon increased birth rates in combination with "sticky" death rates. The fourth theoretical cycle in which death rates lag behind birth rates while both increase has neither precedent nor prospect.