economics Paradigm Challenge

When Brazil made it harder to get sterilized, birth rates shot up—turns out people don't just switch to the pill when their first choice is gone.

March 23, 2026

Original Paper

Female Sterilization Restrictions and Fertility in Brazil

Sergio Firpo, Caio Pedro Castro, Michael França, Lorena Hakak, Alysson Portella

SSRN · 6446592

The Takeaway

Economists and policymakers often assume that if one contraceptive is restricted, people will substitute it with another. This study shows that in middle-income countries, restricting access to tubal ligation leads to a direct spike in unplanned births because substitution is almost non-existent for the most vulnerable populations.

From the abstract

We study the impact of legal restrictions on access to female sterilization in Brazil. In 1997, the Family Planning Law imposed age and parity thresholds for tubal ligation, limiting the availability of the country’s most widely used contraceptive method. Exploiting the eligibility thresholds at ages 21 and 25 in an event-study design with administrative birth records from 1994–2004, we show that affected women experienced significant increases in fertility. Mothers just below the 21 threshold w