Replication package: World prices govern the timing and local climate the location of a perennial crop boom

Specialty tree-crop booms are rapidly reshaping land use and rural livelihoods across the Global South, yet the forces that drive them are seldom observed across an entire expansion. Here we reconstruct a census-grade, year-by-year record of new hazelnut planting across southern Chile from 1992 to 2024---capturing essentially a complete crop boom, from almost nothing in 2005 to the Southern Hemisphere's largest counter-seasonal producer, roughly 48{,}000 hectares. Using a shift-share design that exploits differences in each locality's agro-climatic suitability, we find that world prices and local climate play distinct roles. A one-US-dollar-per-kilogram rise in the world price---which tripled to about ten dollars over the boom---raises new planting by roughly 12\%, concentrated where the climate is most suitable, so prices govern when planting occurs while climate governs where. Price volatility does not robustly delay planting, and no warming-driven frontier emerged, because the region did not warm. These results show how world-market incentives, filtered through local climate, drive the expansion of counter-seasonal perennial crops---clarifying where such booms can be anticipated and whom they reward.