James R. Carey, Professor, Department of Entomology, University of California, Davis, and Senior Scholar, Center for the Economics and Demography of Aging, University of California at Berkeley
Debra S. Judge, Research Ecologist, Department of Entomology, and lectures in the Department of Anthropology, University of California at Davis This article proposes that longevity is not merely the result of an absence of mortality but a self-reinforcing and positively selected life-history trait in social species. It argues that a small increase in longevity is amplified as (1) reductions in mortality at young ages increase natural selection for mechanisms of maintenance and repair at all older ages as well as increasing the potential for intergenerational transfers; (2) intergenerational transfers of resources from old to young increase fitness (e.g., through improved health, skill, and competitive ability) of the young and thus favor the presence of older individuals in a population; and (3)the division of labor increases both efficiency and innovation at all levels, resulting in increased resources that can be reinvested. This theory is framed around the longevity-oriented question posed two decades ago by the gerontologist George Sacher, "Why do we live as long as we do?," rather than the more prevalent question today, "Why do we grow old?" The article describes the foundational principles and the main phases of a model for the evolution of longevity mediated through social organization, and applies the concept specifically to human populations. [27, no. 3 (Sep 01): 411-436]
- First Politics, Then Culture: Accounting for Ethnic Differences in Demographic Behavior in Kenya
Alexander A. Weinreb, National Institute of Child Health and Human Development (NICHD) postdoctoral fellow at the Population Research Center, NORC and the University of Chicago Ethnic differences in demographic behavior tend to be disguised behind analytically opaque labels like "district" or "region," or else subjected to simplistic cultural explanations. Drawing on new political economy, sociological theory and the political science literature on sub-Saharan Africa, this article proposes an alternative explanatory model and tests it empirically with reference to Kenya. Access to political power and, through power, access to a state's resources--including resources devoted to clinics, schools, labor opportunities, and other determinants of demographic behavior--are advanced as the key factors underlying ethnic differences. District-level estimates of "political capital" are introduced and merged with two waves of Demographic and Health Survey data. The effects on models of contraceptive use are explored. Results confirm that measures of political capital explain residual ethnic differences in use, providing strong support for a political approach to the analysis of demographic behavior. [27, no. 3 (Sep 01): 437-467]
- Is There a Stabilizing Selection Around Average Fertility in Modern Human Populations?
Ulrich Mueller, Professor, Institute of Medical Sociology and Social Medicine, Medical School, University of Marburg, Germany Possibly the greatest challenge for an evolutionary explanation of demographic transition is the fact that fertility levels universally start to fall first among the well-to-do, well-educated, healthy classes, which can be explained only by some voluntary or at least adaptive action. The problem of how restraints on fertility could have evolved by natural selection has been tackled with group selection models as well as with stabilizing selection models. The latter model, which is critically discussed in this article, posits that some intermediate (rather than maximal) level of fertility is optimal for long-term reproductive success. Tests of stabilizing selection in human populations are rare, their results inconclusive. Here four sets of data are analyzed: they are samples drawn from the class of 1950 of the US Military Academy at West Point (cohorts 1923-29), retired US noncommissioned officers (cohorts 1913-37), and western German and eastern German physicians (cohorts 1930-35), all containing fertility data over two generations, and from European royalty (cohorts 1790-1939) containing fertility data over four generations. Deterministic as well as stochastic fitness measures are used. It is found that maximal, not average, fertility in the first generation leads to maximal long-term reproductive success. Also against prediction, no decreasing marginal fitness gains by increasing fertility can be observed. The findings leave little space for considering stabilizing selection as a plausible mechanism explaining the course of demographic transition but indicate instead that biological evolution today is as fast and vigorous as ever in human history. Even in large populations, all people living today may be the descendants of just some few percents--a much smaller proportion than generally believed--of the people living some generations ago. [27, no. 3 (Sep 01): 469-498]
- The Age of Migration in China
Zai Liang, Associate Professor of Sociology, City University of New York-Queens College Using data from the 1987 and 1995 China One Percent Population Sample Surveys, this article examines migration patterns during 1982-95, a period of sweeping social and economic changes in China. Several major patterns are evident: the increase in overall migration and especially in temporary migration, the increasing importance of interprovincial migration, and the concentration of migrants in the coastal region. Over time, migrants of rural origin were more likely to choose cities as destinations than towns. The consequences and implications of the changes in migration patterns are explored. [27, no. 3 (Sep 01): 499-524]
Notes and Commentary - Divergent Paths of Immigration Politics in the United States and Australia
Gary P. Freeman, Professor of Government and Director, Public Policy Clinic, University of Texas at Austin
Bob Birrell, Reader in Sociology and Director, Centre for Population and Urban Research, Monash University The United States and Australia converged by the mid-1980s on receptive and expansive immigration policies reflecting "client" politics. Australia has since pursued a more restrictive and selective course while the United States has resisted pressures toward such a stance. The authors account for these differences by assessing the theoretical perspectives of interests, rights, and states. Conflicts among groups with direct interests in policy outcomes are the principal source of immigration politics, but a comparison of the roles of rights and state institutions helps explain peculiarities of the two cases. The distinctive Australian policy trajectory is shaped by greater volatility of public opinion about immigration and multiculturalism, and by political institutions that are more responsive to popular sentiment. [27, no. 3 (Sep 01): 525-551]
Data and Perspectives - The Retrenchment of Marriage: Results from Marital Status Life Tables for the United States, 1995
Robert Schoen, Hoffman Professor of Family Sociology and Demography, Department of Sociology, Pennsylvania State University, University Park
Nicola Standish, Department of Finance, State of California, Sacramento Marital status life tables were calculated using 1995 US rates of marriage, divorce, and mortality. Compared to figures for 1988, the proportion of persons surviving to age 15 who ever marry remained fairly steady at about five-sixths of all men and seven-eighths of all women. The average age at first marriage rose substantially: to 28.6 years for men and 26.6 years for women. The probability of a marriage ending in divorce changed little and was .437 for men and .425 for women. It is likely that no US period or cohort will ever have half of all marriages end in legal divorce, though the highest cohort may reach 47 percent. Patterns of marriage and divorce observed since 1970 show the effect that cohabitation continues to have on the American family, where it is delaying, but not replacing, marriage. [27, no. 3 (Sep 01): 553-563]
Archives - William Farr on the Economic Value of the Population
Book Reviews - Linking Human and Natural History: A Review Essay on J. R. McNeill, Something New Under the Sun: An Environmental History of the Twentieth-Century World, reviewed by Joel E. Cohen
- Population and Progress in the Middle Ages: A Review Essay on David Levine, At the Dawn of Modernity: Biology, Culture, and Material Life in Europe after the Year 1000, reviewed by Jack A. Goldstone
- Julian L. Simon, The Great Breakthrough and Its Cause, edited by Timur Kuran, reviewed by Joel Mokyr
- Angela Hattery, Women, Work, and Family: Balancing and Weaving, reviewed by Dennis Hodgson
- John I. Clarke, The Human Dichotomy: The Changing Numbers of Males and Females, reviewed by Patrick Heuveline
- Giovanni Andrea Cornia and Renato Paniccià (eds.), The Mortality Crisis in Transitional Economies, reviewed by Elwood D. Carlson
- Caleb E. Finch, James W. Vaupel, and Kevin Kinsella (eds.), Cells and Surveys: Should Biological Measures Be Included in Social Science Research?, reviewed by J. Ties Boerma
Short Reviews - Gay Becker, The Elusive Embryo: How Women and Men Approach New Reproductive Technologies
- Theodore Caplow, Louis Hicks, and Ben J. Wattenberg, The First Measured Century: An Illustrated Guide to Trends in America, 19002000
- Stephen Moore and Julian L. Simon, It's Getting Better All the Time: 100 Greatest Trends of the Last 100 Years
- Elisabeth Croll, Endangered Daughters: Discrimination and Development in Asia
- Barbara Entwisle and Gail E. Henderson (eds.), Re-Drawing Boundaries: Work, Households, and Gender in China
- David T. Graham and Nana K. Poku (eds.), Migration, Globalisation and Human Security
- Paul Harrison and Fred Pearce, AAAS Atlas of Population and Environment
- Russell King, Paolo De Mas, and Jan Mansvelt Beck (eds.), Geography, Environment and Development in the Mediterranean
- Michael T. Klare, Resource Wars: The New Landscape of Global Conflict
- Korea Institute for Health and Social Affairs and United Nations Population Fund, Low Fertility and Policy Responses to Issues of Ageing and Welfare
- National Assessment Synthesis Team, Climate Change Impacts on the United States: The Potential Consequences of Climate Variability and Change. Report for the US Global Change Research Program
- Jacques Vallin and Thérèse Locoh (eds.), Population et développement en Tunisie: La métamorphose
Documents - On the Socioeconomic Impact of the HIV/AIDS Epidemic
|
