specificity reduces the influence of forgetting. Anchoring the reporting to the previous interview reduced the possibility of telescoping.

Table 1 presents descriptive statistics on household characteristics across the four survey designs, drawing on the end line survey (postharvest). For these set of traits, households are well balanced across the different survey designs.

To be sure that the differences across the four arms of the experiment are not plagued by confounding factors, we consider some identification concerns. First, households are randomized within villages to account for micro agroecological patterns affecting household labor (which we may not capture through data sources). This raises the possibility of intracluster contamination, whereby one person’s response is influenced by another’s design status. We opt for within-village randomization because we believe that such contamination is unlikely because villages are relatively large and diffuse.

Second, the weekly visits themselves could have caused differential labor (akin to Hawthorne effects). We cannot rule this out, but note two points. There was a general increase in hours as the season progresses (which might occur if respondents started work at a more intensive pace or overreported work as a result of frequent interviews), nor do we find a decline in hours over the season in the weekly interviews because of respondent fatigue. There was also little difference between the face-to-face and phone interviews, whereas one would expect Hawthorne effects to be stronger in in-person visits.

Third, we note that self-reporting rates were similar across survey designs. In the weekly visit group, interviewers were instructed to collect information directly from respondents, where possible, to avoid proxy reporting. Meanwhile, in the weekly phone interviews, one household member typically reported on his/herself as well as on other household members, although the possibility exists that people may have self-reported by turn. In both recall survey designs and consistent with current common practice, interviewers were instructed to ask the most knowledgeable person in the household to report on family farm labor. Despite differences in the instructions given to enumerators and in the feasibility of self-reporting by survey type, the degree of self-reporting achieved was, in fact, similar across the four survey designs of the study. The response rates among self-reporting respondents were as follows: weekly visit (35 percent), weekly phone (33 percent), recall NPS (27 percent), and recall ALT (28 percent).

Finally, attrition was minimal. Households that were surveyed weekly and that dropped out within the first five weeks following the baseline interview were replaced at random from the list of unassigned households. In the weekly visit group, 17 (7 percent) households surveyed in the baseline later dropped out of the study; these were replaced by 14 households, for a total of 212 weekly visit households reporting data for the main season. In the weekly phone group, 14 (6.2 percent) households dropped out, and 12 were added as replacements, for a total of 212 households reporting agricultural labor throughout the season. Replacements were made in this manner up to the sixth week of the weekly interviews. None of the recall survey households declined to participate.

_3.2. Farming practices in Mara_ 9