Africa's expanding population: old problems,new policies

Sub-Saharan Africa faces an historic challenge: to achieve economic and social progress while experiencing extraordinary population growth. With an estimated 1989 population of 512 million, the 42 countries of sub-Saharan Africa have the highest birth and death rates of any major world region. While death rates have fallen since the 1960s, persistently high birth rates yield annual growth rates above 3% in many countries. The United Nations projects that the region's population will increase 2.7 times by 2025--to 1.4 billion. Throughout the region, population has outstripped economic growth since the mid-1970s. In addition, many African countries are experiencing an epidemic of AIDS (Acquired Immunodeficiency Syndrome). The extent and demographic impact of the epidemic still are unknown, but disturbing social and political effects are already being felt. The region's population growth will slow only when African couples begin to have fewer children. The average number of children per woman ranges from 6 to 8 for most countries. The Africans' preference for large families is deeply rooted in the culture and fed by the perceived economic benefits they receive from their children. Economic stagnation during the 1980s prompted many national governments to recognize that rapid population growth was hindering their socioeconomic development. The political climate has shifted away from pronatalist or laissez-faire attitudes toward official policies to slow population growth. The policy formation process--detailed here for 4 countries (Zambia, Nigeria, Zaire, and Liberia)--is ponderous and beset with political and bureaucratic pitfalls, However, policy shifts in more and more countries combined with evidence of increased contraceptive use and fertility downturns in a few countries give some hope that the region's extraordinary population growth may have peaked and will start a descent. Whatever the case, the decade of the 1990s will be crucial for the future of sub-Saharan Africa.     

A Convolution Estimator for the Density of Nonlinear Regression Observations

Abstract. The problem of estimating an unknown density function has been widely studied. In this article, we present a convolution estimator for the density of the responses in a nonlinear heterogenous regression model. The rate of convergence for the mean square error of the convolution estimator is of order n ^?1 under certain regularity conditions. This is faster than the rate for the kernel density method. We derive explicit expressions for the asymptotic variance and the bias of the new estimator, and further a data‐driven bandwidth selector is proposed. We conduct simulation experiments to check the finite sample properties, and the convolution estimator performs substantially better than the kernel density estimator for well‐behaved noise densities.     

A critical survey on the status of multiple criteria decision making theory and practice

This paper seeks to review and to contrast the main streams of thought in Multiple Criteria Decision Making (MCDM) theory and practice, without attempting to review all MCDM methods in detail. The main purpose is to identify pitfalls in the usage of various approaches, and to suggest approaches which are most robustly and effectively useable, especially by the non-expert in MCDM methodology. Problem areas in MCDM still requiring further research are also discussed.     

Sub-Saharan Africa: population pressures on development

The population of sub-Saharan Africa, estimated at 434 million in 1984, is expected to reach 1.4 billion by 2025. The birth rate, currently 48/1000 population, continues to increase, and the death rate, 17/1000, is declining. Rapid population growth has curtailed government efforts to provide adequate nutrition, preserve the land base essential for future development, meet the demand for jobs, education, and health services, and address overcrowding in urban areas. Low education, rural residence, and low incomes are key contributors to the area's high fertility. Other factors include women's restricted roles, early age at marriage, a need for children as a source of security and support in old age, and limited knowledge of and access to modern methods of contraception. Average desired family size, which is higher than actual family size in most countries, is 6-9 children. Although government leaders have expressed ambivalence toward development of population policies and family planning programs as a result of the identification of such programs with Western aid donors, the policy climat is gradually changing. By mid-1984, at least 13 of the 42 countries in the region had indicated that they consider current fertility rates too high and support government and/or private family planning programs to reduce fertility. In addition, 26 countries in the region provide some government family planning services, usually integrated with maternal and child health programs. However, 10 countries in the region do not support family planning services for any reason. Unfortunately, sub-Saharan Africa has not yet produced a family planning program with a measurable effect on fertility that could serve as a model for other countries in the region. Social and economic change is central to any hope of fertility reduction in sub-Saharan Africa. Lower infant and child mortality rates, rising incomes, higher education, greater economic and social opportunities for women, and increased security would provide a climate more conducive to fertility decline. Given the limited demand, great sensitivity must be shown in implementing family planning programs.