The Problem
County averages are 30 years old. Fields aren't.
USDA RMA county loss-cost factors are multi-decade averages built from voluntary hand surveys aggregated across thousands of farms. A drought in one township while the adjacent township gets adequate precipitation still registers as one county-level number — erasing the within-county variance where adversely selected risk actually concentrates.
Commodity traders face the same structural gap. USDA WASDE publishes once a month. Intra-season crop development — stress events, recovery signals, yield trajectory shifts — happens on a 5-day satellite cadence. The 30 days between WASDE publications are a structural information asymmetry.
"Up to 34% yield variation within single RMA county units — USDA NASS county-level analysis"