This policy temporarily ceased in 1986. One empirical study points out that
import-substitution strategy associated with high protection through the overvalued exchange
rate was notably against primary exports, whilst promoted manufacturing firms reaped the
economic gains at the expense of the rural poor (see Siamwalla and Setboonsarng, 1989).
The question is whether high economic growth rate after the mid-1980s might have been
explained by the demographic transition. To some extent the fact that higher income leads to
lower birth rates as found by Brander and Dowrick (1991) might be the case. Fertility
declines precede income growth gains or in other words, income growth has a negative effect
on fertility