During the first, post-planting survey visit, each treatment group household completed a short parcel-plot-crop-level module on farm organization, which listed all parcels and plots within, in accordance with the IHS5 parcel and plot definitions.<sup>4</sup> Once the roster of parcels and plots was completed, one maize plot was selected at random. The manager of this plot was the target respondent for questions on the rest of the activities occurring on this plot. The target respondent then self-reported the plot area. Subsequent to the respondent self-reporting the selected plot size, the enumerator and respondent visited that plot together. The enumerator measured the plot area with a handheld Garmin eTrex 30 GPS unit,<sup>5</sup> then recorded and shared with the farmer both the GPS-based plot area and the measurement error in farmer-reported area vis-à-vis the GPS-based counterpart (both in levels and as a share of GPS-based plot area).<sup>6</sup> This was the information treatment, a demonstrably accurate measure of the plot area.<sup>7</sup> After finishing the plot visit, the enumerator and the farmer returned to the dwelling to administer the rest of the post-planting questionnaire, which asked the farmer to self-report labor, fertilizer and other inputs used on the plot before and during planting.

During a second, post-harvest visit to each treatment household,<sup>8</sup> the respondent was asked again to report the selected plot area, whose GPS-based measure had been shared with the respondent during the post-planting visit. If the self-reported plot area was different than the GPSbased plot area, the respondent was asked again his/her recollection of the GPS-based plot area. The respondent then re-reported all labor and non-labor inputs on the plot, in view of the possibility of non-labor input applications not having been finalized at the time of the post-planting interview.

Conversely, control group households received a single, post-harvest visit during which they completed a unified agricultural questionnaire, including the same self-reporting of plot size,

> 4 A parcel is defined as a continuous piece of land that is not split by a river or a path wide enough to fit an oxcart or vehicle. A plot is continuous piece of land on which a unique crop or a mixture of crops is grown, under a uniform, consistent crop management system.

> 5 After walking the perimeter of a given plot with the plot manager to identify the boundaries, the enumerators measured the area with the GPS unit. The NSO enumerators were experienced users of the handheld GPS technology, which was adopted by the NSO for land area measurement in 2010 in the context of the Third Integrated Household Survey and the Integrated Household Panel Survey (IHPS).

> 6 Once the GPS-based plot area information was imputed into the Survey Solutions Computer-Assisted Personal Interviewing (CAPI) application, the measurement error was calculated and displayed automatically.

> 7 We cannot gauge the extent to which the sampled farmers trusted the GPS-based plot area measures and therefore cannot test whether mistrust of objective evidence might help explain highly imperfect updating of self-reported plot area.

> 8 The post-harvest visit was scheduled according to the households’ harvest calendars, as the primary purpose of this visit was to harvest and weigh the crops on pre-designated crop cut sub-plots on the selected maize plot.

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