The Shade Trap: Seven Ways a Cold-Chain Pilot Overstates Its Result, and a Pre-Purchase Screen That Catches Them

Postharvest cooling pilots can produce persuasive but misleading results when cooling is bundled with better handling, assessment timing is left undefined, clustered units are treated as independent, infrastructure costs are omitted, or observed losses are attributed to heat without a controlled comparison. This methodological commentary examines seven recurring design traps and presents a practical Gate 0 pre-purchase screen for determining whether a particular site and cooling pathway justify a controlled trial before equipment is purchased. It distinguishes trial eligibility from purchase approval, requires pathway-specific commercial thresholds, defines genuinely independent experimental units, and explains why sample size must be based on the gap between the planned effect and the improvement needed to justify investment. A one-page review checklist is included. The paper does not claim that cooling is ineffective or that the screen can estimate cooling’s effect. Its purpose is to help funders, implementers, researchers, and cooperatives determine whether a proposed pilot can produce evidence strong enough to guide a capital decision.