IN Initially American women in the 1970s gave birth to an average of 2.12 children each. By 2018, the figure had dropped to 1.73. Many changes have been requested in people’s lives to explain this change, including the fact that women are now better educated, have jobs or run businesses, and have better access to contraception than their ancestors did five decades ago. Also, children are required to work extra pairs on family farms.
None of these revelations nicely overlap with the birth rate curve. Other factors should also be at work. And Jordan Nickerson and David Solomon, professors of finance at the Massachusetts Institute of Technology and Boston College Ledge, respectively, think they’ve got an interesting response: America’s increasingly protective child car-seat laws.
Published in his study, “Car seats as contraceptives” SSRN, A repository for so-called printprint papers that have yet to receive a formal peer review, examines the impact of car-seat policies on American birth rates between 1973 and 2017. During the Reagan era, only true old age required children under the age of three to be safe on safety seats. But the state governments have since gradually increased the requirements. Today, most places in America make children sit on safety seats until their eighth birthday. That concern for the safety of youngsters has had unintended consequences, as Dr. Nic Nicholson and Dr. Solomon suggest, there are at least three child families.
In drawing this conclusion they have correlated the change in state law on safety seats with census data. They found that there was no detectable effect on the birth rate of the first and second children when the laws were tightened, but the average number of women giving birth to a third was a drop, despite an average of 0.73 percentage points. Young enough for the need for safety seats. It may not sound like much, but it is a significant fraction of the 9.36% of women in the sample who became a third-time mother.
The authors also made two other relevant observations. The decline they saw was limited to homes that actually had car access. And he grew up in a house where a man lived with his mother. They believe, the latter point is relevant, as this person will replace the vehicle that can be occupied by a child.
And vehicle space is the deciding factor. In the days before safety, squeezing three young children into the back of a family salon was a potential proposition. Most such cars can comfortably accommodate only two safety seats. Therefore, the child must be large before a safety seat is necessary, the family must wait a long time before a third child can fit in the car. Sometimes, that wait means that a third child is never conceived and born.
Unless, of course, the family concerned buys a big car. And here things get even more interesting, for obvious reasons not to do so – the bigger the car the more expensive it is, and the more expensive it is to drive. Changing can not be the only refusal to change it. Dr. Nic. Nikkarson and Dr Solomon found in fact that the prevention of a third child appears strong in wealthy families. As they observe, “Large cars like minivans also have class and aesthetic meaning that can make people reluctant to switch even when they can afford it.”
Back-seat driver
Oddly enough, though, the authors don’t leave it at that. Instead, they draw attention to previous studies that suggest that, for more than two children, safety seats are no better than seat belts to protect against death or serious injury in a crash. They estimate that children need to sit on special seats until they are eight years old, with about 57 people saving lives in 2017, and this number is in stark contrast to the 8,000 children conceived and born in the absence of these rules. There, they conclude, there is no “compelling social interest” in requiring child seats for more than four children.
This sounds weird. Comparing the saved life to the forgotten pagan life is to put it mildly, a strange moral calculation. And the empirical basis for it is, in any case, questionable. Alyssa Bear, a pediatrician in New York who specializes in car-seat safety and says she has installed at least 15,000 such seats over the years (known as the “car seat lady”), says this is part of the paper. “Absolutely reprehensible”. Children’s car seats, he says, “protect the quality of life” of children, who suffer from higher rates of injury compared to belting, including only abdominal pain and paralysis. A recent study by Mark Anderson at Washington University and Cena Sandholt at Columbia University has shown this issue.
However, Dr. Nic. Knickerson and Dr. Solomon Solomon cannot move away from extensive observation, nor can well-intentioned actions lead to surprisingly hard-hitting effects. And one such, it seems, the rear seats of American cars, once known as the spaces children imagined, could now act as contraceptives on their own.■
This article appeared in the Science and Technology section of the print edition under the title “Birth Control”
