The problem would ultimately be overcome through further economic development together with educational and other social change. Nevertheless, the legitimization of marital discussion of birth control was not achieved until the subject was written about in the press and subsequently in birth control manuals sold on a much larger scale than before. This, in turn, changed the packaging and accessibility of contraceptives, making their discussion, acquisition, and use easier and a fertility decline possible. Despite ongoing declines in fertility in many countries, the population of the world is experiencing a period of rapid expansion, and its size is expected to reach 10 billion by the end of the demographic transition. A set of simple analytic expressions is proposed for estimating these factors from standard demographic indicators.
Population momentum is shown to be the main cause of future growth in most countries and regions.
The present essay suggests the role that Darwinian theory can play in the study of human fertility. After examining the nature of Darwinian theory, the essay considers research carried out on fertility by biologists and anthropologists with methods based on it and possible reformulations of demographic methods and analyses that could benefit fertility research. It ends with suggestions for further research to explore the value of Darwinian approaches to demographic issues. LLC While an extensive literature documents the need for better measures of women's work, few attempts have been made to construct suitable work typologies that could be applied throughout the developing world. The author argues that in addition to the descriptive utility of more-comprehensive measures of women's work, important analytical gains are to be made by applying better measures of work to a variety of research questions.