Each EA was assigned to a specific enumerator.P12F<sup>13</sup> As noted above, the fieldwork ran for 12 months. During the first month, all sampled households were visited for the first time. In this first visit, the enumerators administered a light multi-topic questionnaire to all sampled households in a given EA, collecting basic information on household demographics, economic activities, dwelling attributes, farm and durable asset ownership, along with detailed information on all gardens and (within-garden) plots owned and/or cultivated.P13F<sup>14</sup> These questionnaire modules did not vary by survey treatment, and were based on the comparable Malawi Integrated Household Survey (IHS) questionnaire modules. In addition, irrespective of the survey treatment, the enumerator obtained the plot areas and the outlines for the cassava plots cultivated by the CVIP households, using a handheld Garmin eTrex 30 GPS unit.P14F<sup>15</sup> The respondent reported the area of each cassava plot,P15F<sup>16</sup> and irrespective of the survey treatment, one cassava plot was selected at random in each household for crop cutting, as explained in section 3.2. During the first visit, the enumerator also laid down a 5x5m crop cutting sub-plot, following a strict randomization protocol, on the selected plot in each household.P16F<sup>17</sup>

# **3.1. Survey Treatments**

CVIP implemented two diary- and two recall-based survey treatments. The enumerators scheduled visits to the CVIP households in strict observance of the requirements of each survey treatment arm (in terms of timing and frequency).P17F<sup>18</sup> For all questions regarding agriculture and cassava migration and the respondent died in 2 1-member households. There was no other loss of sampled households due to refusal and all diary households kept their diaries for as long as they had cassava standing on their plots during the fieldwork period.

13 The experiment used 15 enumerators, and each enumerator covered 3 EAs. EAs were divided among the staff in such a way that enumerators could reside within one of their EAs or a nearby district center, and bicycle to their assigned households.

> 14 A garden ( _munda_ ) is defined as a continuous piece of land that is not split by a river or a path wide enough to fit an ox-cart or vehicle. A garden can be made up of one or more plots. 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. It must be a continuous piece of land and must not be split by a path of more than one meter in width. Plot boundaries are defined based on the crops grown and the operator.

15 After walking the perimeter of a given plot with the plot manager to identify the boundaries, the enumerators repaced the perimiter and measured the area with the GPS unit.

16 The allowable units for self-reported plot areas were square meters, acres and hectares. The majority of respondents reported in acres, with approximately 5 percent reporting in hectares or square meters.

17 Further, the enumerator obtained a leaf sample from each sub-plot for objective variety identification based on DNA fingerprinting. Each leaf sample was associated with a barcode that was scanned by the Survey Solutions CAPI platform to enable the linkage between the lab results and the household survey data. The assessment of the relative accuracy of farmer-reported variety names and attributes, in comparison to DNA fingerprinting-based cassava variety identification, is the subject of a separate research study.

18 Given the within-EA proximity of CVIP households to one another, it is possible that the enumerators and the respondents may have seen one another on a more frequent basis than the intended research design. For instance, when an enumerator performed his/her semi-weekly visits to the D1 households or was living day-to-day life in his/her EA of residence, he/she might have inevitably interacted socially with the other CVIP households nearby. While we have 8