Rapid changes over the last twenty years have impacted every branch of demographic analysis, from birth rates and immigration, to marriage rates and aging. "The Nature of Demography" is a response to these enormous changes. Written by one of the world's leading demographers, this authoritative text offers a systematic and coherent overview of the fundamental ideas governing the study of present and future populations. This book covers formal models as well as the underlying logic and context of demographic reasoning. The text also illustrates recent data and new methodological developments.The first section of this book discusses measurements that involve a single individual, such as mortality and fertility; the second section moves from individual behaviors to population-level phenomena; and, the third section looks at models involving individuals and social structures within the population, such as marriage and migration rates - topics not addressed in such detail in any other demography text. Written for advanced undergraduates and experienced researchers, "The Nature of Demography" contains a wealth of material that will inspire innovative applications in the field. An up-to-date and authoritative textbook by one of the world's leading demographers, it provides: creative use and critique of demography methods; comprehensive and innovative coverage of marriage, migration, and economic demography; and, explanations that reach beyond mathematical formulas to underlying theories of behavior.