Sorghum as Insurance against Drought: Demand for Bird-Resistant Sorghum and Its Effects on Household Outcomes among Zambian Farmers

In the BDM auction to elicit willingness to pay for 3kg of sorghum seeds, we randomize purchase prices at 0, 20, 40, 60, or 80 ZMW across households. Given this randomization, we compare outcomes between households that adopt sorghum and those that do not, even when they have the same WTP.

2026-09-10

2026-10-31

Primary outcome variables are willingness to pay elicited through the BDM auctions for seed type k (k=red, white).

Primary outcome variables on the production side are: 1. land size cultivated; 2. cultivation methods; 3. expenditure on seeds; 4. family and hired labor supply to each farm activity (e.g., land preparation, planting, weeding, bird scaring, and harvesting); 5. quantity of chemical fertilizer applied; 6. maize and sorghum yield; 7. participation in farmers’ input subsidy program; 8. agricultural profit; 9. profit from non-farm self-employment activities; and 10. earnings from piecework. Primary outcome variables on the consumption side are: 1. food consumption; 2. non-food consumption; 3. dietary diversity; and 4. time use (e.g., schooling).

Our target is the 846 households that received either red or white sorghum seeds in September 2022 as part of a randomized controlled trial in five wards in Sinazongwe District, Southern Province, Zambia.
During the survey period from September-October 2026, we will visit each target household twice. During the first visit, we will conduct three activities: 1) a short household survey, 2) practice rounds using a bar of regular soap to familiarize respondents with the BDM mechanism, and 3) the BDM auction for 3kg of sorghum seeds for production purposes. Specifically, we will measure WTP for ZSV36R (red variety) and ZSV17 (white variety) for each respondent, although only one variety will ultimately be auctioned. The market price of both ZSV36R and ZSV17 is 372 ZMW per 10 kg. For the BDM auction, the randomly drawn purchase price will be 0, 20, 40, 60, or 80 ZMW per 3kg, with each price having a 20% chance of being drawn. Approximately one week after the first visit, we will meet the target households again at a designated public location to finalize the BDM transactions, including the exchange of money and seeds for households whose bids result in a purchase. In July-August 2027, we will follow up with the surveyed households to ask about agricultural practices during the 2026/27 rainy season and other economic activities.

Not available

Randomization done in office by a computer

Agricultural households

No

846 households

846 households

0 ZMW assigned to 170 households, 20 ZMW assigned to 169 households, 40 ZMW assigned to 169 households, 60 ZMW assigned to 169 households, and 80 ZMW assigned to 169 households. This is a theoretical allocation, and the final sample size by treatment arm depends on the resulting attrition rate.