Endogenous Fertility and the Environment: A Parable of Firewood

Abstract

This chapter discusses a model which examines interactions between population growth and the environment. In this model, various assumptions are made such as that fertility is endogenous; parents are not altruistic and have children only because of utility; environmental deterioration does not affect population (i.e., no ‘Malthusian’ mortality); time is measured in generations; and population pressure adversely affects the environment. The model gives a system of two non-linear difference equations. The main conclusion is that in the absence of parental altruism and ‘Malthusian’ mortality, the relation between population and environment is inherently unstable when fertility is endogenous. Thus, when parents are concerned only about the utility (net private benefits) and environmental resources are not priced (free), parents may choose the number of children which is optimal from their point of view but which will ultimately lead to environmental degradation.

Environmental and population externalities

“…Nerlove (1991), and Nerlove and Meyer (1997) derive a similar conclusion in a dynamic framework. These models are coined on regional environmental problems of rural areas in developing countries.…”

Food Security, Fertility Differentials and Land Degradation in Sub-Saharan Africa: A Dynamic Framework

“…One example of such a vicious circle is illustrated by the parable of firewood (Nerlove and Meyer 1997). Gathering firewood, water, etc.…”

“…2 Hence, Nerlove and Meyer (1997) argue that " [t]he relation between fertility and environmental degradation depends primarily on the way parents perceive the benefits of having children and not primarily on the effect of population size on the environment, as long as the environment is adversely affected by larger population". Similarly, Dasgupta (1993) finds that in poor countries children are also considered as income-earning assets which provides an additional motivation for having children.…”

Human Fertility Decisions and Common Property Resources: A Dynamic Analysis

“…While there are empirical studies describing the resource-gathering role for child labor in poor countries and the potential linkages between population, poverty, and the local environment, only Nerlove [1991Nerlove [ , 1993 and Nerlove and Meyer [1997] have pursued an understanding of their interaction in a more theoretical context. Their model is similar to the one developed in the current paper, in that it is a two period overlapping-generations model, in which individuals spend the first period of their lives as children supporting their parents by exploiting local environmental resources, and spend the second period living from the support of their own children.…”