Intertemporal Choice and Income Regularity: Non-Fungibility in the Timing of Income Among Kenyan Farmers

The optimal design of informal contracts in agricultural value chains depends on when farmers prefer to be paid for their output. While the evidence from the time preference experiments suggests a preference for early payments, field studies often indicate that farmers will defer regular payments if given the opportunity. In this study, we explicitly test whether farmers are more patient regarding regular, earned income than regarding experimental windfall payments. We asked farmers in a dairy cooperative in Kenya to allocate both their milk income and a one-time gift between an early and a deferred payment date. We find that a large majority of participants deferred their milk payments, while rarely choosing to defer the gift. Participants’ survey responses suggest that we observe this difference because of mental accounting: participants earmarked their regular milk payments, but not the gift, to save for bulky expenditures. We conclude that deferred payments can provide value to producers by functioning as a savings device, even when decisions over windfall income suggest a preference for early payments. We are sharing the data collected through this experiment as well as our do-files for replication and further analysis purposes.

农业价值链中非正式契约的优化设计，取决于农户对其产出报酬的兑付时机偏好。现有时间偏好实验的证据显示农户更倾向于提前获取报酬，但实地研究往往表明，若有机会，农户会选择推迟常规报酬的领取。本研究专门检验：相较于实验性意外所得，农户对常规劳动所得是否更具耐心。我们邀请肯尼亚某乳品合作社的农户，将其乳品销售收入与一笔一次性赠与金，分别在提前兑付与延迟兑付两个日期间进行分配。研究发现，绝大多数参与者选择延迟领取乳品销售收入，但极少选择延迟领取赠与金。参与者的问卷反馈表明，这一差异源于心理账户（mental accounting）效应：农户将常规乳品销售收入定向用于储备大额支出，而未将赠与金作此规划。我们由此得出结论：即便针对意外所得的决策显示农户偏好提前兑付，延迟兑付仍可通过充当储蓄工具为生产者创造价值。本研究将本实验采集的数据集及用于复现研究与拓展分析的Do文件（do-files）一并公开，以供后续使用。