This paper studies whether Minnesota’s Buffer Law affected county-level corn and
soybean yields. Using a staggered difference-in-differences design that compares Minnesota
border counties to neighboring border counties, we estimate dynamic effects
while controlling for weather, drought, fertilizer use, and adoption intensity of federal
conservation programs. We do not find consistent evidence that the law reduced average
yields in the later post-treatment periods. The current results are preliminary and
should be interpreted cautiously pending additional robustness and sensitivity analysis.
