Over the past 20 years, the number of working women has gradually increased, and
women have become a substantial portion of most national labor markets. As an important and
growing source of production, female labor supply contributes to overall per capita incomes,
impacts household income distribution, and affects fertility rates. Female labor force
participation and concomitant investments in human capital have important external effects in
the form of childbearing and childrearing, especially in low income countries (Schultz 1995).