Children & fert_devt.jpgPopulation Growth

Most countries have experienced a significant decline in fertlity rates in recent decades. Half the world, including all of the rich world, is at or near the so-called replacement rate of fertility, in which each mother is raising one daughter on average to "replace" her in the next generation. The poorest of the poor countries, by contrast, are stuck with fertility rates of five or more. On average, a mother is raising at least two girls, and in some cases three girls or more. In those circumstances, national populations double each generation. Rapid population growth can create a poverty trap. When impoverished families have large numbers of children, the families cannot afford to invest in the nutrition, health, and education of each child. They might only be able to afford the education of one child, and may send only one son to school. High fertility rates in one generation, therefore, tend to lead to impoverishment of the children and to high fertility rates in the following generation as well. Rapid population growth also puts enormous stresses on farm sizes and environmental resources, thereby exacerbating poverty. However, this demographic trap is avoidable. Girls' education would allow women to more easily join the labor force, increasing their earning power and the "cost" of staying home to bear children. Education, law, and social action can empower women to more easily make fertility choices (instead of having those choices made solely by husbands or others in the family). Children can be treated for disease to better ensure their survival, meaning that parents can have fewer children, feeling secure that they will survive to take care of their parents in old age. Family planning and reproductive health services can be provided even in very poor countries. All of this requires money, however, and money is lacking in the poorest countries. The figure on the right shows how the total fertility rate in the year 2001 compares with the country's national income per person. Here is the demographic trap in vivid perspective: the poorest places, many with the greatest obstacles to modern economic growth, are also the places where families have the most children and where the populations continue to soar.

In the MV Sim, you control your family's decision to attempt to have a child and the success of the pregnancy depends on the health of the mother. Children under 5 have a higher probability of sickness and death. Children between ages 5-10 can contribute to family income, but cannot get enough food for subsistence on their own. Alternatively, the children can attend school. Children between ages 10-15 can work for the entire day and be able to cover their subsistence needs, but again, this would mean not going to school.

At the village level, the population grows with a constant birth rate and non-malaria death rate. Malaria mortality occurs in addition to the "background" death rate, and during severe epidemics could even cause a decrease in village population.