Although mathematical demography has traditionally studied the so-called stable population (fixed mortality and fertility schedules), Ansley Coale investigates now the dynamics of population growth and structure—the changing age composition of a population as birth and death rates fluctuate. Originally published in 1972. The uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.