Increases in Medicaid eligibility during the 1990s slightly increased the incidence of smoking during pregnancy, according to a new working paper by the National Bureau of Economic Research. The authors — Dhaval Dave of Bentley University, Robert Kaestner of the University of Illinois and George Wehby of the University of Iowa — cited their finding as one possible explanation for why the program failed to improve infant health outcomes.
“We find that increases in Medicaid eligibility were associated with increases in smoking and decreases in weight gain during pregnancy,” the authors wrote. “Raising Medicaid eligibility by 12 percentage points increased rates of any prenatal smoking and smoking more than five cigarettes daily by 0.7-0.8 percentage point.”
The effect is largest on single mothers with less than a high school education.
The authors have two possible explanations for why more expectant mothers on Medicaid would smoke. The first is straightforward: Medicaid coverage leaves some patients with more money to spend on cigarettes. This explanation would apply especially to those who enroll in Medicaid after dropping private insurance.
The other explanation is classic moral hazard — a willingness to take greater risks in the knowledge that care is free, as crazy as that may sound in this case.
“Insurance lowers the price of treating an illness, for example, an adverse medical outcome for either the mother or child, which may cause a reduction in maternal efforts to prevent the occurrence of such events,” the authors wrote. Backing up this idea is that the effect is especially pronounced for previously uninsured patients who become eligible for Medicaid. “The adverse effects of expanded coverage on health behaviors are stronger at lower levels of eligibility, which is consistent with the fact that more individuals are shifting from being uninsured to being insured at these levels,” the authors wrote.
The study helps explain why Medicaid expansions have failed to improve infant health outcomes, the authors say.
The data studied were from 1989-97, so the effects of Medicaid expansion through Obamacare are not included.
