production, the enumerators attempted to interview the plot manager(s) or household member(s) most knowledgeable about decision-making on the gardens and plots owned and cultivated by the household. Table 1 provides an overview of the incentives that were provided to the CVIP households and that are detailed below.

# **3.1.1. Diary Arms**

The first group of households (D1) were given a diary to record cassava harvest on a daily-basis, across a 12-month period, under the supervision of an enumerator that visited them twice a week. Harvest diaries were also filled by the plot manager(s). If any plot manager was illiterate, the enumerator assisted the respondent in identifying another literate household member to assist them in weighing the cassava and filling the diary. The enumerator visits were meant to encourage good record keeping; record information on harvests that had been omitted by the respondent; field questions on the specifics of diary keeping; assist with the weighing of the fresh harvest if it coincided with the visit; and solicit information on the likely timeline for crop cutting on the selected cassava plot. To facilitate D1 household diary keeping, each respondent was provided a total cash incentive of approximately US$7, distributed in two installments.<sup>19</sup> The second group of households (D2) were too given a diary to record their cassava harvest on a daily-basis for 12 months. However, instead of in-person monitoring visits, the D2 households received calls on their mobile phones twice a week. The inclusion of this treatment arm was intended to assess the feasibility and accuracy of using mobile phones to collection production data on a frequent basis as a potential cost-saving alternative to avoid having to pay resident enumerators to perform in-person visits to households. Additionally, it allowed for centralized supervision with upper management able to check on the quality of the call center operators’ performance at any time. The phone calls were initiated from a call center that was set up at the NSO Headquarters in Zomba and that was supervised daily by the NSO CVIP fieldwork coordinator. The initial visit to all households within the first weeks of fieldwork served as the baseline survey for the D2 households. At this visit, the enumerators clearly outlined the purpose of the project and the expectations in terms of recording all cassava harvested and the importance of keeping their phone charged to receive the bi-weekly calls. Additionally, enumerators distributed the mobile phones, SIM cards, and solar chargers at this visit and demonstrated how to use the different components.

> no data on the extent of these interactions, the enumerators were given a firm instruction to not discuss any aspect of CVIP data collection outside the scheduled visits to the sampled households. Throughout the fieldwork, the CVIP fieldwork coordinator and team leaders followed up with the enumerators regularly also to ensure that the CVIPrelated interactions with the households were taking place in accordance with the intended research design.

> 19 The first installment was provided when the crop cut sub-plot was laid on the selected plot. The second installment was provided at the end of the survey.

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