One of the more exciting sessions I went to at the recent Centre for the Study of African Economies Conference was on the relationship between agricultural plot size and productivity. I walked out of the session not sure of the shape of the relationship, but I was sure of the fact that there is a lot of measurement error going on. And this is measurement error that matters a lot.
So there I was, a graduate student doing my PhD fieldwork. In the rather hot office at the University of Ghana, I was going through questionnaire after questionnaire checking for consistency, missed questions and other dimensions of quality. All of a sudden I saw a pattern: in the time allocation questions, men in one village seemed to be doing the exact same things, for the same amount of time, on two very different days of the week.
I just got back from two weeks visiting a bunch of ongoing projects in Africa. During the trip, the issue of community entry came up again.
About 15 years ago, when I was doing my dissertation research with a professor with experience in fieldwork, we did a 15 round survey with households in Ghana. Given the frequency of the visits, we based the enumerators in the village. But we were careful to hire enumerators from nearby big towns -- not the villages in which we were working. This was partly for skills, but mostly to make sure that the enumerators wouldn't be asking sensitive questions of people they knew.
A couple of days ago, my wife and I were having one of the moments -- I was convinced we had had a detailed conversation about something and she was convinced that no such conversation had taken place. Now, if you were to show up and do a survey of us, we wouldn't agree.