The Dynamic Relationship between Low Birthweight and Induced Abortion in New York City: An Aggregate Time-Series Analysis

We use a vector autoregression to examine the dynamic relationship between the race-specific percentage of pregnancies terminated by induced abortion and the race-specific percentage of low-birthweight births in New York City. With monthly data beginning in 1972, we find that induced abortion explains low birthweight for blacks, but not for whites. There is no evidence of feedback from low birthweight to induced abortion. Simulations based on the model reveal that an unanticipated decrease in the percentage of pregnancies terminated by induced abortion results in an increase in the rate of low-birthweight births among blacks. The findings suggest that restrictions on legalized abortion in New York City would worsen birth outcomes among blacks.