Mortality
World population growth has resulted from marked reductions in mortality rates due to improved health care, education and sanitation, especially in the developing world. For example, a quarter of Sri Lanka's decline in mortality after 1945 has been attributed to malaria control.
Mortality rates have fallen dramatically in ssa from just under 30 per 1000 in 1950 to some 16 per 1000 in the early 1980s. This decline reflects the general increase in living standards, education and public health programmemes.
While birth rates have also fallen, they remain significantly above death rates in the developing world and only slightly above in the developed world. It is this factor which provides the proximate explanation for the difference between developed and developing world experience. In the developed world, reductions in mortality rates were generally accompanied by reductions in birth rates. Reductions in birth rates in the developing world have lagged behind reduced mortality rates, and in a number of cases the birth rate has hardly fallen at all.The reasons for the constancy in the birth rate are found in underlying cultural attitudes to the bearing of children, and in economic factors. As health improves, so does natural fecundity (the physiological ability to bear children). Age at marriage for girls in Africa has not declined significantly. There is some evidence that breastfeeding and post-natal sexual abstinence have declined, and there is an extremely low use rate for contraceptives. The factors underlying these proximate reasons for the continued high birth rate appear to be as follows:
  • the continuing agricultural bias in African economies. This provides incentives to "invest" in children as labour on the farm: assisting with fuelwood and water collection, caring for children, looking after livestock, etc. Moreover, the amount of land that can be cultivated often depends on family size, creating further incentives for large families. The private benefits from increasing family size thus tend to outweigh the private costs, and this determines family size , decisions. The net private benefits will tend to diminish, and eventually become negative above a limited family size, as education opportunities expand, as off-farm employment opportunities increase, and as land tenure and ownership patterns change. State- provided education incurs private costs in the form of uniforms, books and travel, making larger families more costly. Urban work opportunities reduce the need for on- farm labour, and tenurial change reduces the incentive to claim resource and land rights on the basis of family size;
  • larger families act as a form of social security through the extended family. Being a child frequently involves many obligations to other members of the family. Once again, "investing in children" becomes a way of ensuring care in old age. More generally, larger families mean wealth and influence. As state- provided social security systems are introduced, so this motive for larger families will weaken;
  • as long as women have an inferior social role to men, any preferences they might have for smaller families will be under- represented in the private cost-benefit decision about family size. Often, however, a woman's own status depends on childbearing, so that women appear to share the preference for large families. As education expands and other forms of emancipation increase, so some women might be expected to change their preferences for large families, while others, with a prevailing but overruled preference for smaller families, might be expected to exert more influence;
many cultures simply favour large families. Women are afforded