ARE CAR SEAT LAWS DRIVING DOWN AMERICA'S BIRTHRATE?

• Author: Britschgi, Christian
• Position: POLICY

A PROVOCATIVE NEW study claims the steady upward creep in the age at which states mandate that children use car seats is prompting women to either postpone or opt out of having a third child.

The paper, published on the Social Science Research Network, by finance professors Jordan Nickerson of MIT and David Solomon of Boston College, argues that most vehicles can fit only two car seats in the back row, necessitating the purchase of a larger car to accommodate three young children at once. That added cost, they argue, disincentivizes some women from having a third child.

"We find that when a woman has two children below the car seat age, her chances of giving birth that year decline by 0.73 percentage points" below where they'd be if only one or none of her existing children were required to be in a car seat, write Nickerson and Solomon. "This represents a large decline, as the probability of giving birth for a woman age 18-35 with two children already is 9.36 [percent] in our sample."

The nationwide average minimum age at which children are allowed to ride in cars with just seat belts has risen from less than 3 in the mid-1980s to just under 8 today. This steady increase, the paper suggests, could help explain why fertility rates have declined in the last decade despite a long-running economic recovery that would normally encourage more childbirths. To tease out the impact of car seat...