Rural cooperative cold-chain fee tiers and women's perishable-produce market participation in Kenyan wards: a regression-discontinuity estimation of storage-cost thresholds

The central problem is that fee schedules are set at discrete thresholds, so the effect of storage cost on participation is identified only at the discontinuities those thresholds create. Because no primary survey data were collected for the present analysis, the paper is framed as a methodological and theoretical contribution: it formalises the fee-tier mechanism, derives the estimand, and sets out the data requirements and validity checks that an empirical application would need. The design is calibrated against the DHS Program indicator 'Discontinuation due to cost' (FP_RDIS_W_CST), which provides a real benchmark for the scale of cost-driven behaviour change: across 73 country-survey observations in 28 African countries between 1992 and 2025, the indicator has a mean of 0.714 and a standard deviation of 0.649, with country values ranging from 0.05 in Morocco to 1.95 in Benin. Fee-tier discontinuities are a credible and underused source of identification for storage-cost effects, and that the design's value lies in making the threshold structure of cooperative pricing explicit rather than treating storage cost as a continuous variable.