Car seats as birth control? A new study explains the decline in three-child families

Could child safety seat regulations act as an unintended form of birth control?


That’s the assertion of two professors in a study called “Car seats as contraception.” First reported by The Economist this week, the study found that increasingly restrictive child car seat laws have led to fewer families with three children between 1973 and 2017. 

Several other factors attribute to the American birth rate for women who give birth dropping from 2.12 children in the 1970s to 1.73 children on average in 2018. Women’s equality, including more women who are better educated and excelling in the workforce, as well as increased access to contraception, help explain the cultural shift more than car seat laws.

But increasingly restrictive child safety seat laws, which progressed from securing only children under age three in safety seats in the 1980s to now securing children in safety seats at least until they’re eight years old, have had an undeniable effect on having a third child, according to Jordan Nickerson and David Solomon, professors of finance at the Massachusetts Institute of Technology and Boston College, respectively.

According to their findings, the birth rate dropped 0.73% in women giving birth to a third child when the other two children still needed safety seats. The reduction may seem small, but The Economist reports it was a significant fraction of the 9.36% of women in the sample who became third-time mothers.

The authors make a convincing case when combined with other variables: The reduction applied only to households with access to a car and in situations where a man was living with the mother—and ostensibly occupying another seat in the car.

The data provides a direct correlation, the authors say, with vehicle space being the crucial factor. Fitting three kids in the back seat or even the way back seat in wagons of a certain vintage was never a problem in the wild west safety days of the ’80s. Now, fitting three child safety seats in an SUV’s second row has become a selling point, such as in the 2021 Volkswagen Atlas2021 Subaru Ascent2021 Kia Telluride, and all the minivans.

Could this mean a return to more American families with three children?

That remains to be seen. What’s clear is Americans prefer larger cars and this study hasn’t been peer reviewed. 

Leave a comment