[varunramesh]

According to the paper, "The data include the infant’s month of birth, and a clinical estimate of gestation in weeks, which we use to estimate a month of conception."

On miscarriages, "We interpret these data with caution because they come from a subset of one state, and because fetal deaths are under-reported. Nevertheless, the data provide no evidence of an increase in miscarriages leading up to recessions that is anywhere near the magnitude required to explain a significant portion of the observed decrease in births." They similarly argue that abortions aren't significant enough to explain the reduction in births.