RESUMEN
Between 2016 and 2018, we observe in Uruguay a steep decline of almost 20 percent in the number of total births, leading to the collapse of the adolescent fertility rate after decades of relative stagnation. We estimate the quantitative contribution on birth rates, especially teen births, of a policy of expanded availability of subdermal contraceptive implants. We exploit the expansion schedule of a large-scale policy of free-of-charge access to subdermal implants in the country's public health system through an event study to capture causal effects. We use detailed birth administrative records for the past 20 years. We document an average reduction of 3 percent in the birth rate in public health facilities across the two years after the policy was implemented in each department. These reductions were notably higher among teens and first births. Although changes in women's fertility decisions are a multicausal phenomenon, we claim that the expanded availability of subdermal contraceptive implants accounted for one-third of the teen and young women's birth collapse.