Economic consequences of post-harvest insect damage in Rwandan common bean markets. (February 2018)

• Record Type: Journal Article
• Authors: Jones, Michael S.; Alexander, Corinne E.; Smith, Bruce
• Is Part Of: Crop protection. Volume 104(2018)
• Page Start: 92
• Page End: 100
• Publication Date: 2018-02
• Subjects: Post-harvest losses -- Crop storage -- Storage technology -- Common beans -- Rwanda -- Sub-saharan africa; Plants, Protection of -- Periodicals; 632.05
• DOI: 10.1016/j.cropro.2017.10.015
• Languages: English
• ISSNs: 0261-2194

Abstract

Abstract: Post-harvest losses have major economic consequences for smallholders in sub-Saharan Africa. One significant contributor to economic losses is price penalties for poor quality marketed grain. This study investigates farm-gate level discounts demanded by rural Rwandan bean traders for insect-damaged common beans. We use a simplified contingent valuation methodology with physical bean samples to elicit seasonal damage discount schedules based on data from 270 trader interviews in 25 regionally-diverse rural markets, in periods of both common bean abundance and scarcity. While levels of 5–10% insect damage can generally be sold with a moderate discount, beans with 20–30% insect damage are largely unmarketable. We model the physical and non-physical drivers of buying insect-damaged beans and, if so, the extent of discounts demanded. Results indicate that while insect damage levels play a central role, large volume traders penalize damage less while traders in the seed market, storing before re-sale, or purchasing heavily from farmers (vs. other traders) penalize damage significantly more. Findings help develop more evidence-based extension programming and methods could be adapted as an easily implemented and potentially insightful model for developing country agencies. Additionally, derived discount coefficients help evaluate the cost-effectiveness of technologies throughout the region which prevent post-harvest damage. Highlights: We survey bean traders throughout Rwanda in periods of scarcity and abundance. We use a simple method for market research on post-harvest insect economic impacts. We examine traders' market rejection and price penalties for insect-damaged beans. After storage each 1% seed damage increases rejection by 2.5% and discounts by 0.8%. Traders who are smaller, storing, and buying directly from farmers discount greater.