able and willing to practice effective birth control when motivated economically. Fertility is thus
to some degree a voluntary choice variable within marriage even in pre-industrial societies.
As the Industrial Revolution progressed in Europe and real wages increased, fertility
nonetheless began to decline widely by the end of the 19th century. The Malthusian framework
needed to be amended further to fit this experience in Europe and be applicable to low-income
countries after 1960 as new methods of family planning were disseminated in the world and
fertility fell despite modern economic growth. How was the secular decline in fertility to be
explained in the face of rising personal incomes? The decline in child mortality, which gathered
speed after 1870, reduced the need for parents to have extra births to replace the one out of five
who might have at earlier times died from childhood diseases and infections. Parents might also
scale back their demand for ‘insurance’ births motivated to reduce the likelihood that a couple
would sustain above average child losses (Schultz, 1981). Becker (1960) proposed that the
relative price of rearing children increased over time, causing the decline in parents’ demand for
children. Mincer (1963) hypothesized that an increase in women’s wages increased a couple’s
opportunity cost of having children, raising the shadow price of children. He argued that the rise
in female labour-force participation and the decline in fertility were both caused by conditions
increasing women’s wages relative to other consumer prices and men’s wages. These empirical
patterns in the United States were soon replicated in other high-income countries.
Changing the relative prices of outputs of the economy is one possible source of variation
in women’s wages relative to men’s that could explain changes in fertility. Men’s labour in
European agriculture was critical for plowing and producing food grains, whereas women
specialized in home production as domestic servants and wives and to some degree in animal
husbandry and the production of dairy commodities. Consequently, changing scarcity of grains
relative to livestock and dairy product contributed to swings in the relative wages of men and
women in Europe. The secular decline in international grain prices relative to dairy and livestock
prices in the latter half of the 19th century was unprecedented due to the opening of new lands at
the frontiers of European settlement in the United States and Russia, and contributed along with
changes in production technologies to the rise in women’s agricultural wages relative to men’s in
northern Europe and to the decline in fertility. Swedish historical data by region document after
1860 the fall in world grain prices, the associated increase in the wages of women relative to men,
and the secular fall in fertility, when other developments are controlled for (Schultz, 1985).