ABSTRACT
As with mortality, there is a clear statistical relationship at the global scale between fertility and development. Those countries with highest per capita incomes and the most favourable HDI tend also to have the lowest fertility (Figure 5.1). Fertility levels are highest in sub-Saharan Africa, and in 2013 were estimated to be highest in Niger, with a TFR of 7.6, and Chad with 7.0, that is, each woman on average bearing over seven children during her lifetime (see Box 5.1 for discussion of measures of fertility). By contrast, many European countries have TFRs of less than 2, and so also some Middle Income Countries such as China (1.3), Thailand (1.6) and Taiwan (1.3), and thus below replacement level: that is, unless there is immigration, within one generation there will be population decline as the number of births is below the number of deaths. In Latin America there is considerable divergence within the overall trend of fertility decline, with TFRs ranging from 3.98 for Guatemala to 1.47 for Cuba. That there is this immediately apparent statistical relationship between fertility and development does seem to imply a direct and straightforward causal relationship between them. However, the relationship between them is far from simple. Alternative, and in some senses competing, explanations of the apparent relationship between fertility and development, the chief of which are rooted in cultural variables associated with marriage and the family, will be explored in this chapter. The most familiar of the explanations of the relationships between fertility and development has already been elaborated in the assumptions and mechanisms of the DTM (as discussed in Chapter 3) that fertility and mortality are systematically related, and that fertility changes in response to changes in mortality. Fertility levels and trends at any given time seem to have been a lagged response to mortality levels. Since mortality has been
falling globally and at different rates in different world regions, for the range of reasons identified in Chapter 4, so fertility has followed, from a high equilibrium level of a TFR of about 5 when life expectancies were low to a lower level, and eventually to a low-level equilibrium with a TFR at about 2 and replacement level. The main implication of the DTM is that the transition from high to low equilibrium, resulting in long-term low population growth after a period of rapid growth, has been driven by a range of universal development impulses of the last 250 years. The basis of the transition model is that fertility and mortality are intrinsically interrelated and analytically both have responded to similar factors, including modernisation, urbanisation and education, and that the end-point of the transition is a low-level equilibrium between them.
