in the post-harvest period, following the same set of fieldwork protocols that had been used in the prior IHPS rounds.

The IHS5 2019/20 is the second source of survey data in Malawi. Unlike the IHPS 2019, the IHS5 is a cross-sectional survey that is designed to be representative at the national-, urban/rural-, regional- and district-levels. The IHS5 sample includes a total of 11,434 households, distributed across 717 EAs throughout Malawi.<sup>8</sup> The fieldwork was implemented from April 2019 to April 2020, and each sampled household was visited once. The households that were determined to have owned and/or cultivated any land reported information on the last completed rainy season, which could have been 2017/18 or 2018/19 depending on the interview date.

The IHPS 2019 and the IHS5 2019/20 used identical, extensive agricultural questionnaires that elicited information at the parcel-, parcel-plot-, and parcel-plot-crop-level, depending on the topic. Of particular importance to our research is that the surveys identified each crop cultivated on each plot, and in the process, determined whether a given plot was monocropped or intercropped. Further, each cultivated plot that was determined to be within 2 hours of travel (irrespective of the mode of transport) was attempted to be visited with the farmer. The plot area was captured with a Garmin eTrex 30 handheld global positioning system (GPS) unit, and the plot location was georeferenced in two ways: (i) the enumerator captured the GPS coordinates for the corner point at which the plot area measurement commenced and manually inputted the GPS coordinate into the computer-assisted personal interviewing (CAPI) application (i.e. the corner point method), and (ii) the enumerator also captured the perimeter of the plot during the plot area measurement exercise and stored the resulting geospatial polygon on the GPS unit following a naming convention that facilitates the linking of the polygon to the plot record in the household survey data (i.e. the full boundary method).

We refined the initial data set to isolate the best quality data for the analysis. Plot records were retained only if they possessed both a corner point and a full plot boundary and had a crop type record for the reference rainy agricultural season. Furthermore, if the location information (either corner point, or plot boundary, or both) was duplicated across two or more plots, we dropped all duplicated records, except in cases where one, and only one, of the duplicated records had a high degree of confidence assigned to their location data quality - in these cases, the record with the high degree of confidence was kept and the remaining records were dropped. Lastly, only records with a high degree of confidence in the location data quality (both for the corner point and the plot boundary), as indicated by a metric provided by the GPS unit, were retained. We treated plots that were cultivated with any maize as “maize plots”, and otherwise labeled them as “non-maize.” Tables 1 and 2 show the IHPS 2019 and the IHS5 2019/20 rainy season plot observations, broken down by georeferenced information availability and by maize cultivation status, respectively. The final analysis sample includes 2,792 IHPS 2019 plots and 5,794 IHS5 plots associated with the

> 8 See the IHS5 2019/20 basic information document for more information: http://bit.ly/ihs201920.

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