[Demographic influence on economic stability: the United States experience]. / Influencias demograficas en la estabilidad economica: la experiencia de Estados Unidos.

PIP: Up to the 1930s the international migration rate into the U.S. was very high, while birth and mortality rates had little variation; migration was, therefore, the principal responsible for population growth rate. Migration cycles were induced by economic conditions, and had, in their turn, important effects on economic feedback. The growing of urban areas, i.e., accelerated demand for new homes and urban services in general, prolonged the economic expansion. After World War 2 a new period opened in the relation between demographic and economic cycles. At the end of the 1950s the U.S. experienced a considerable growth in the number of people between 15-29, due to corresponding birth rate increase, which initiated around 1940. This marked difference in the relative number of young adults, or manpower, resulted in an economic situation relatively unfavorable. For the future a decrease in the relative number of young adults is expected, reflecting the decrease in birth rate experienced around 1960. If the U.S. should experience a new "baby boom" in the next few decades, radical changes in the demographic composition of manpower will have to be expected.^ieng