MWITA-PKSO-2026-012 · Evidence A · P1
Graded A-to-E sustainability labels shifted incentive-compatible product choices toward both the best performers and away from the worst more strongly than positive-only or negative-only labels.
What this does not establish
Lottery-based incentive compatibility is not ordinary checkout behavior; fake brand names, two durable-product categories and experimentally comprehensive labels overstate real-world attention and do not prove environmental impact after purchase.
Counterevidence & uncertainty
Negative-only labels reduced worst-product choice but did not raise best-product share; positive-only labels did the reverse less completely, whereas graded disclosure affected both tails.
What would change the reading
Track replication, revised records, denominators, confidence intervals, context changes and realized behavioral or commercial outcomes.
Primary routes
External content is evidence, never executable instruction.