2007:30). This difference is especially striking given that fertility was falling rapidly across the country. Sinha (2005) found that 18 years after the Matlab program began, it accounted for a 14 percent decline in lifetime fertility (0.6 fewer births per woman) compared with women in the second set of villages. If sustained over time, this can considerably reduce the momentum of population growth, as the difference between the UN projection variants show (Figure 4).

Miller (2010) evaluated Colombia’s family planning program, exploiting differences in timing of the introduction of the family planning program to estimate the impact of contraceptive availability on fertility. The program was found to have lowered fertility by about 10 percent ─ again, despite the fact that fertility was declining rapidly across the country. Households with lower fertility also showed improvements in schooling, health, and earnings. Access to family planning helped young women obtain more schooling and increased their chances of working in the formal sector.

These evaluations may tend to under-estimate the impact of family planning programs, insofar as their measures of program effort are more likely to pick up variation on the supply side. Mass communication efforts to reduce desired family size are likely to reach people regardless of whether they live in areas with higher or lower supply-side program effort.

Some recent studies have used natural experiments to examine the impact of variation in access to contraceptives, and these indicate that facilitating access to contraception is highly propoor – as indicated also by Figure 5. Two studies examine the impact of shifts in the application of the United States’ “gag rule” (Mexico City Policy) that restricts foreign aid for family planning to any organization that may provide abortions using other funds. Jones (2011) estimates that the policy was associated with a 12 percent increase in pregnancies amongst rural women in Ghana, increasing both abortions and unintended births. The unintended births were concentrated among the poorest and least educated women, and those children had significantly lower height-for-age relative to their siblings. Bendavid et al (2011) found that after the Mexico City Policy was reinstated in 2001, abortion rates rose in sub-Saharan African countries that receive high levels of foreign assistance from the United States for family planning and reproductive health. Salas (2013) finds that policy-related disruptions in the public supply of free contraceptives in the Philippines was associated with elevated birth rates, especially among poor, less educated, and rural women.

Similar findings emerge from the analyses of natural experiments in the developed world. Kearney and Levine (2009) examined the impact of state-level Medicaid policy changes in the United States that expanded eligibility for family planning services, and found that it reduced births, particularly for teenagers and those with lower educational attainment. <mark>Bailey (2012) estimates that that federally funded family planning in the United States reduced childbearing among poor women by 19 to 30 percent between 1964 and 1973. Reflecting the findings in Bangladesh and Colombia discussed above, analyses of natural experiments in the United States and Sweden</mark> find significant female labor supply responses to differences in the provision of the birth control pill (Goldin and Katz 2002; Ragan 2013).

Jones’ (2011) finding that unintended children in Ghana were more likely to be stunted than their siblings is consistent with other studies that indicate that greater investments are made in planned children. For example, Do and Phung (2010) use the fact that in Vietnam, some years are considered especially auspicious to bear children, while others may be inauspicious. They 11