Michael J. New highlights a methodological limitation in a recent abortion study promoted by Amanda Marcotte and others:
A medical student contacted the authors of the study to ask how they obtained pregnancy and abortion data from study participants. As it turns out, the researchers used telephone surveys. Overall, this is extremely problematic. Many women who submit to an abortion will not voluntarily reveal that information. As such, this study likely undercounts abortions and overestimates the effectiveness of contraceptives. This is obviously a significant methodological limitation to the study — one no mainstream-media outlet has yet to cover.
This is a reminder of how careful one must be in citing sociological data. If our beliefs are correct, we can expect reality to conform to them, but working the other way is harder if not impossible. We won’t strike upon first principles or basic commitments while sifting through fine-grained data. The real argument will always be deeper.