Let me tell you a wonderful story, a statistical detective story of sorts.
During the summer, you may have seen statistics released from the 2010 Census Summary File 1 on same-sex couple unmarried partner households.
We noticed that reported counts of same-sex couples from the 2010 census were much higher than similar estimates from American Community Survey at earlier years. Our demographic analysts had some immediate ideas, explained nicely in this video:
So we suspected that the format of the nonresponse followup form was the culprit. If that were the case, one should see some obvious mismatches between the name of the person written on the form and the recorded sex of that person. Bingo! A qualitative inspection of some of the records showed suspicious combinations (e.g., “Harold” recorded as a “female”). Past research led us to believe that the name entered was likely to be more accurate than the recorded sex.