DEMOGRAPHIC TRANSITIONLife Expectancy PatternsLife Expecenty in Years, 1986Life Expecenty in Years, 1998
30 40 50 60 70 8030405060708090Figure 1
societies due to factors (Bongaarts 1975) that have
little relationship to conscious desires such as
prolonged breastfeeding which supresses repro-
ductive ovulation in women, the effectiveness of
birth control methods, and the amount of involun-
tary foetal abortion. As a result of these analytic
ambiguities, scholars seem to have less consensus
on the social factors that might produce fertility
than mortality decline (Hirschman 1994; Ma-
son 1997).
Coale (1973), in an attempt to reconcile the
diversity of circumstances under which fertility
declines have been observed to occur, identified
three major conditions for a major fall in fertility:
- Fertility must be within the calculus of
conscious choice. Parents must consider it
an acceptable mode of thought and form
of behavior to balance the advantages and
disadvantages of having another child.
2. Reduced fertility must be viewed as so-
cially or economically advantageous to
couples.
3. Effective techniques of birth control must
be available. Sexual partners must know
these techniques and have a sustained will
to use the them.
Beyond Coale’s conditions, little consensus
has emerged on the causes of fertility decline.
There are, however, a number of major ideas
about what causes fertility transitions that may be
summarized in a few major hypotheses.A major factor in causing fertility change may
be the mortality transition itself. High-mortality
societies depend on high fertility to ensure their
survival. In such circumstances, individual couples
will maximize their fertility to guarantee that at
least a few of their children survive to adulthood,
to perpetuate the family lineage and to care for