Sex and the Birth Rate: Human Biology, Demographic Change, and Access to Fertility-Regulation Methods
Malcolm Potts, Bixby Professor, School of Public Health, University of California, Berkeley, and President, International Family Health, London Success, in evolutionary terms, means contributing more surviving offspring to the next generation than competing individuals of the same species in the same population. Human conception is a probabilistic event occurring against a background of frequent, usually infertile sex, which helps bond parents together. Humans have an innate drive for sex and for nurturing their children as they arrive, but they have no biological predisposition for a specific number of children. In preliterate societies, in the absence of artificial means of fertility regulation, pregnancies are spaced several years apart by unconscious physiological mechanisms based on breastfeeding. In preliterate and in preindustrial urban societies, socially successful individuals commonly had larger than average families. Once people have unconstrained access to a range of fertility-regulation options (including safe abortion), family size falls in all groups and in all societies. In such a context, social success tends to be associated with the accumulation of material wealth, rather than with having more children. The argument that development causes fertility decline is flawed because people cannot make choices about family size without realistic access to fertility-regulation technologies, and such access is historically recent and remains geographically limited. Where access to fertility regulation is constrained, the richer and more educated are usually better able than the less privileged to surmount the barriers between them and the needed technologies, hence the common inverse relationship between income and family size. Policies derived from this perspective are discussed. [23, no. 1 (Mar 97) 1-39]
Variability and Growth in Grain Yields, 1950-94: Does the Record Point to Greater Instability?
Rosamond Naylor, Senior Research Scholar and Fellow, Institute for International Studies, Stanford University
Walter Falcon, Farnsworth Professor of International Agricultural Policy and Director, Institute for International Studies, Stanford University
Erika Zavaleta, doctoral candidate, Department of Ecology and Evolutionary Biology, Princeton University The outcome of the "race" between population and food is of enduring contemporary interest. The two variables that are set opposite each other in the race are fundamentally different in character. Population is primarily a stock concept that rises monotonically, whereas food production is overwhelmingly a flow variable that exhibits substantial year-to-year fluctuations. These latter fluctuations, in turn, cause significant economic and nutritional consequences at the household level. Assessing the pattern of these annual fluctuations in cereal yields with respect to their magnitude, geographic incidence, and change over time is thus of evident interest in questions concerning food security. This article assesses the growth and variability of corn, wheat, and rice yields from 1950 to 1994 on a global and regional basis. The results suggest that any broadly held notions of greatly increasing instability in global grain yields are probably wrong. More important, yield variability has not risen significantly between 1950 and 1994 in the developing world as a whole. Instability in corn yields has increased, however, in the developed world--particularly in North America--and in Africa. Higher yield variability is not necessarily a portent of disaster, but adjustments in trade, livestock, or storage are not instantaneous, automatic, or costless. Even world-food "optimists" need to worry about the possible effects of two or three successive "bad" corn crops in North America. [23, no. 1 (Mar 97) 41-58]
Shifting Costs of Caring for the Elderly Back to Families in Japan: Will It Work?
Naohiro Ogawa, Professor, College of Economics, and Deputy Director, Population Research Institute, Nihon University, Tokyo
Robert D. Retherford, Senior Fellow, Program on Population, East West Center, Honolulu Over the next 30 years the percentage of Japan's population who are elderly will rise rapidly to unprecedented levels, and the country's population will become the oldest in the world. The financial pressures on Japan's social security system will be severe. To alleviate these pressures, the government is attempting to shift some of the costs of the social security system back to families. But fundamental economic, social, and value changes, discussed in this article, are eroding the capacity of the Japanese family to care for elderly parents. It is therefore unlikely that the government will succeed in shifting the costs appreciably. [23, no. 1 (Mar 97) 59-94]
Modernization and Divorce: Contrasting Trends in Islamic Southeast Asia and the West
Gavin W. Jones, Professor and Head, Division of Demography and Sociology, Research School of Social Sciences, Australian National University During the 1960s and 1970s, divorce rates rose to unprecedented levels in Western countries but plummeted in Islamic Southeast Asia from initially very high values in the 1950s and earlier, continuing thereafter to fall to levels well below those in the West. In Islamic Southeast Asia, explanations emphasize radical change in the mate selection context, linked in particular to extended periods of education for girls, whereby the couples contracting marriage gained a greater stake in its success. Greater wealth, less polygyny, and social and religious pressures to tighten divorce procedures all played a role. In Western countries, by contrast, increased emphasis on individualism and postmaterialist values are usually stressed. In the West, promotion of women's well-being emphasized the ease of breaking from unsatisfactory marriages; in Islamic Southeast Asia, the avoidance of entering into such marriages. Although sharing some common elements, the two regions started from such different situations that their divorce trends must be explained in their own terms rather than according to a universalist theory of divorce. [23, no. 1 (Mar 97) 95-114]
Notes and Commentary State Policies and the Birth Rate in Egypt: From Socialism to Liberalism
Philippe Fargues, Research Director, Institut National d'Études Démographiques (INED, Paris), currently Director, Centre d'Études et de Documentation Économique, Juridique et Sociale (CEDEJ, Cairo) This note explores the influence that state policies have had on the decline of the birth rate in Egypt during the second half of the twentieth century. The three successive political regimes over this period have pursued similar policies seeking to extend the practice of birth control. Despite this continuity in population policy, the birth rate has exhibited several shifts, alternatively downward and upward, indicating the influence of other factors. The erratic variations of the birth rate, in the short term, appear to parallel the resources available to households, which in turn change in relation to public policies affecting the distribution of income and, more recently, the increasing dominance of market processes in the economy. On the other hand, the long-term trend toward a decrease in the birth rate is paralleled by an increase in the average level of education among women, which for its part results from state policies extending schooling to girls. These results suggest that the analysis of population policies should not be isolated from the global political economy that forms the context of the fertility transition. [23, no. 1 (Mar 97) 115-138]
Data and Perspectives Anthropogenic Factors in Land-Use Change in China
Gerhard K. Heilig, Senior Research Scholar, International Institute for Applied Systems Analysis, Laxenburg, Austria The author analyzes five anthropogenic driving forces of land-use change in China: population growth, urbanization, industrialization, changes in lifestyles and consumption, and shifts in political and economic arrangements and institutions. The intention is to demonstrate the broad range of factors other than biogeophysical conditions that will affect future land-use patterns in China. A first set of statistical data was collected to analyze these demographic and socioeconomic trends. The author also includes new estimates on China's cultivated land area, indicating that it is more seriously underreported in official statistics than previously acknowledged. [23, no. 1 (Mar 97) 139-168]
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