decision making by adolescent girls at the time of choice. Interventions in the second category are intended to influence sexual decision making indirectly by developing and strengthening adolescents’ motivation to avoid early childbearing. They are based on the assumption that broadening opportunities, especially through educational enhancement, will provide meaningful alternatives to childbearing.

The aim of this paper is to investigate the potential of the second strategy: does education reduce early fertility and if so, by how much? Investing in education is one of the most emphasized components of development: in Kenya, 22.9% of the State budget is allocated to education<sup>3</sup> . Education can contribute to favorable changes in demographic outcomes in several different ways. First, the “incarceration” effect: educational attendance reduces time available to engage in child bearing, thus postponing the decision to have one’s first child. This could be particularly true in Sub-Saharan Africa, where national laws forbid pregnant teenagers from attending school in most countries (CBASSE (1993)). Second, the “knowledge” effect: better educated women have more knowledge about contraception and family planning. Third, the “autonomy” effect: women with higher education earn higher incomes, decide to have fewer kids of better quality, pair with men who have the same preferences for children as they do, have more power to be respected in their own fertility decisions (Jejeebhoy (1995)). In all three cases, if women tend not to have children while continuing to attend school, there should be a natural and rather mechanical effect of schooling on fertility, thus delaying the beginning and possibly shortening women’s reproductive life in developing countries (Amin (1995), Jensen (2003)).

In developing countries, where teenage fertility rates are much higher than in industrialized countries (see Table 1), the debate about education and fertility timing has very real consequences. Sub-Saharan Africa still displays some of the highest levels of fertility in the world, including adolescent childbearing. In Kenya alone, the rate of girls aged 15-19 who were pregnant was 114‰ in 2003, compared to 10h in OECD countries. 39.4% of teenagers aged 15-19 have already given birth once (2003). Much of the high fertility can be attributed to young age at first sex, young age at first union, and young age at first birth (Mahy and Gupta (2002)). In addition, desired fertility in Kenya is much lower than current fertility (DHS (2003)).

We provide here new evidence on the role of increased schooling on early fertility, drawing on a quasi-experiment in Kenya. We exploit a radical change in the Kenyan educational system, implemented in 1985, that increased by one year the time necessary to complete primary school. This change in the curriculum affected all kids at most in their second to last year of primary school in 1985. Students subject to the Reform graduated from primary school after a minimum of 8 years (instead of 7) and secondary school after 4 years of schooling<sup>4</sup> . This discontinuity is used to instrument the number of years spent in school and circumvent the endogeneity of choice between schooling and childbearing.

Our paper shows that higher levels of education decrease by at least 10 percentage points the probability of giving birth when still a teenager (taking the most conservative results). Knowing that the probability of having one’s first child before age 20 when having at least completed primary education is about 65%, this entails a reduction of about 15% of teenage fertility rates (for those having at least completed the KCPE). One additional year of school curbs the probability of becoming a mother each year by respectively 7.3 and 5.6% for women with at least a primary and at least a secondary degree.

> 3 Source: UNESCO statistics. 4 When they did not repeat a grade.

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