Disaggregation in population forecasting: do we need it? And how to do it simply

"We have described a method for reducing the dimensionality of the forecasting problem by parsimoniously modeling the evolution over time of the age schedules of vital rates. This method steers a middle course between forecasting aggregates and forecasting individual age specific rates: we reduce the problem to forecasting a single parameter for fertility and another one for mortality. We have described a number of refinements and extensions of those basic methods, which preserve their underlying structure and simplicity. In particular, we show how one can fit the model more simply, incorporate lower bounds to the forecasts of rates, disaggregate by sex or race, and prepare integrated forecasts of rates for a collection of regions. We also discuss alternate approaches to forecasting the estimated indices of fertility and mortality, including state-space methods. These many versions of the basic method have yielded remarkably similar results." (SUMMARY IN FRE)     

Low fertility in Malaysia: Can it be explained?

Journal of Population Research - This study assesses the determinants of the fertility rate in Malaysia using the combined tests for cointegration and generalised variance decomposition analysis of...     

Young unwed fathers of afdc children: do they provide support?

We examine the support provided by fathers of children born to disadvantaged teenage mothers. Our sample includes the fathers of 6,009 children born over a two-year period to 3,855 teenage mothers receiving AFDC in three economically depressed inner cities. These fathers provide little social and economic support to their children. Support declines as their children age from infants to toddlers and as fathers’ relationships with the mothers grow more distant. Fathers’ employment status and educational attainment positively affect the amount of economic support that they provide but do not strongly influence the amount of social support they provide.     

Sub-replacement fertility in national populations: Can it be raised?

This paper comments on the four main functions demographers perform: fact-finding, analysis, prediction, and policymaking. Successes in the first two of these are counterbalanced by weakness in predictive ability. The focus of the comments, however, is on policy. Demographers were influential in promoting efforts to lower very high fertility but are ineffectual in proposing policies that could reverse the tendency of fertility to sink well below replacement levels. The paper argues for a break from exclusive reliance on the standard measures of modern welfare states intended to raise fertility and urges exploration of radically new approaches. Two promising innovations are briefly outlined: one would give the right to vote to all citizens regardless of age, the voting right of minors being exercised by parental proxy, and another that would reform state-administered pension schemes by arranging a direct transfer of working children’s mandatory contributions to social security funds to their retired parents.     

Injectable contraceptives: how safe are they?

Controversy still surrounds the use of the injectable contraceptive, Depo-Provera, in 3rd world countries, when it has yet to be approved in the US, Canada, Japan, and other developed nations. Some medical professionals maintain Depo is both safe and effective and could curb rapid population growth worldwide. With no conclusive decision made, some countries have approved Depo while others have not yet decided. Originally approved for a variety of uses, Depo is approved in the US only as a treatment for advanced endometrial cancer; however, it is now available in 65 countries and is used as a contraceptive in the Philippines. Depo and its companion Norigest are both progestonogenic injectables and were developed in the late 1950s. Injectables inhibit ovulation and thicken cervical mucus, thereby preventing fertilization. The reservoir usually lasts from 3-6 months, and its action cannot be reversed until the body has completely absorbed the drug. Injectables are highly effective; most accidental pregnancies occur shortly after the 1st injection before the drug has taken effect or at the end of an interval when its effect is wearing off. Overall the rate of fertility return corresponds to the rates for the pill and the IUD. Injectables have the advantage of preventing side effects brought on by estrogens; thus they would be beneficial to women desiring to use contraception but who cannot manage pill side effects. They do not interfere with lactation and have the lowest failure rate of the reversible methods. Important to developing countries is that injectables require no effort on the part of the user. Injectables do disrupt the menstrual pattern and Depo use often results in weight gain. Little is known about the longterm risks of Depo; however, in 1973 the US Food and Drug Administration withdrew approval of Depo for pregnancy-related uses because of links to birth defects. Other recent studies have uncovered other possible effects including uncertainty about whether injectables affect the composition of breastmilk or whether they raise blood glucose levels. Ethics have entered into the controversy with the "contraceptive double standard" where Depo has been exported to 3rd world nations when it has been ruled unsafe for American women. Campaigns have been organized against the distribution and use of injectables in the developed nations and a few in the 3rd world have begun to organize. While the Philippines has approved Depo, it is not yet considered an official method of the National Population Program. Policymakers await a more thorough analysis of factors for and against the promotion of the drug.     

How low can it go? declining black-white segregation in A multiethnic context

We extend research on whites’ neighborhood contact with blacks, population composition, and prospects for desegregation by developing a new measure of the floor of racial residential segregation under conditions of low black-white contact. The measure incorporates the way in which multi ethnic contexts further constrain levels of black-white segregation. The results show that black-white desegregation is likely when the black population is small, but is unlikely otherwise. Yet, when multiple ethnic groups are sufficiently large, a moderate level of black-white segregation is necessary for whites to maintain low neighborhood contact with blacks, even when the proportion of African Americans is small.     

Has a discipline come of age when it can boast several competing dictionaries?

The authors review three recently published reference works in demography: the International Encyclopedia of Population, edited by John A. Ross; the Dictionary of Demography, by Roland Pressat, edited by Christopher Wilson; and the Dictionary of Demography: Terms, Concepts, and Institutions, by William and Renee Petersen. They also consider what the publication of such works tells us about the development of demography as a discipline.     

Internal migration: why do Filipinos move?

The rapid movement of Filipinos from 1 part of the Philippines to another is not a new phenomenon, but mobility has been increasing. A study conducted by Peter C. Smith revealed that interprovincial lifetime mobility of the national population increased from 15.8% in 1960 to 17.6% in 1970, while interregional mobility increased from 12.7% to 13.4%. People still disagree as to whether the size and rate of growth of the population are excessive, but there seems to be total consensus as regards its spatial imbalance. Because internal migration appears to be an important factor in national development, a need exists to examine different aspects of internal migration, such as the directions taken by migration flows, the migrants' reasons for moving, the migrants' characteristics, the migrants' success or lack of success at their places of destination, the social problems accompanying internal migration, effforts to deal with the problems caused by internal migration, and the implications of migration trends for policy and for the country's development programs. The most dominant migration trend in the Philippines in recent years has been toward the urban, or more accurately the suburban, areas adjacent to Metropolitan Manila. The city of Manila itself suffered a net outflow, further pointing to the trend toward suburbanization. Migration flows are primarily caused by economic reasons. About one half the sample of a Filipinas Foundation Study moved to provinces other than the province of birth in the pursuit of employment and other economic opportunities. A study of the country's migrant population age 15 and older showed that 53% of migrants were female. For male migrants, age ranges from 20-40; it ranges from 15-35 for females. Where cash income is concerned, migrants in Pernia's study of rural urban migration were better off than nonmigrants. Migrants were, on the average, as well off as native urbanites or metropolitanites. Among the more significant points raised by scholars and researchers are the following: urbanization is an inevitable and irreversible process, and it is wise to plan for it; the problem is not rapid urbanization but unbalanced urbanization, i.e., the concentration of urbanization in Metro Manila; steps to alter national urban patterns might include establishing a migration guidance office; the need exists for an explicit, firm, and consistent population distribution policy; and solutions that anticipate problems having to do with internal migration and prevent these problems from arising will, in the long run, be more effective than curative solutions.     

Whites who say they'd flee: who are they,and why would they leave?

Questions have been raised about whether white flight--one factor contributing to U.S. residential segregation--is driven by racial, race-associated, or neutral ethnocentric concerns. I use closed- and open-ended survey data from the Multi-City Study of Urban Inequality to explore who says they would leave and their reasons for doing so. Thirty-eight percent of white respondents said they would leave one of the integrated neighborhoods, with Detroiters and those endorsing negative racial stereotypes especially likely to do so. When asked why they might leave, whites focused on the negative features of integrated neighborhoods. Expressions of racial prejudice were also common, but neutral ethnocentrism rare. The results of an experiment asking about integration with Asians and Latinos are also discussed.     

The population explosion: Where is it leading?

Over the past few centuries world demography has been characterized by both continuous absolute growth and a steadily increasing rate of growth. From 1650 or earlier to at least 1957 it was always possible to say that never has world population been so large and never has the time necessary for it to double been so short. While there are now some signs to suggest that population doubling times are stabilizing, or even increasing, the population increase in absolute numbers is nevertheless greater each year, and the rate of growth may still be faster than a simple exponential function. There can be little doubt that too large a population, together with the pressures stemming from its demands for an even higher standard of living, sets requirements greater than our planet can safely sustain. This article reviews some aspects of global population data and population dynamics.     

Indigenous fertility in the Northern Territory of Australia: what do we know? (and what can we know?)

In the Northern Territory of Australia, Indigenous people make up 30% of the population. Demographic features of the Indigenous population are thus important for understanding Northern Territory population dynamics, but our understanding of what is happening within the Indigenous population is limited by poor data and limited research attention. This paper exploits birth registration and census data to explore Northern Territory Indigenous fertility trends over a 20-year period. It investigates whether fertility decline identified for the 1960 and 1970s is a contemporary feature of Indigenous fertility in the Northern Territory. Results show that our understanding of Northern Territory Indigenous fertility is heavily constrained by data and that trend analysis is essential for avoiding erroneous conclusions because of annual fluctuations. The outstanding feature of Indigenous fertility in the Northern Territory is women becoming mothers at extremely early ages, particularly in rural and remote parts of the Territory. Age patterns appear to have changed little since the middle of last century despite modest declines in age-specific fertility at the youngest ages. While these declines may continue, any trends will be slow to emerge. Continued close scrutiny of data sources and monitoring of trends is needed to ensure that Northern Territory population dynamics are properly understood, and care must be taken in interpreting results to make certain policy interventions aimed at population outcomes are appropriate and achievable.