["Agribusiness, EarlyView. ", "\nABSTRACT\nThis paper asks whether municipalities with a larger export‐to‐revenue ratio display a more concentrated bundle of exported goods in Brazilian agribusiness. Recent advances in export imputation for Brazilian municipalities allow for an analysis of the concentration profile of each municipality and its association with export openness. We make three contributions: we develop an Export‐Intensive Gini Index based on Monte Carlo simulations that isolates commodity‐specific concentration while accounting for the composition of the remaining export portfolio; we apply a double machine learning estimator to characterize the partial association between openness and concentration while controlling for hundreds of municipal characteristics covering geography, infrastructure, demography, and institutions; we provide a cross‐sectional description, for 2023, of subnational export concentration in a developing economy using production‐based rather than customs‐based trade data. Results show heterogeneity across commodities. Coffee displays the strongest positive association between export openness and concentration, followed by corn, soybeans, and sugar, while beef displays a negative coefficient. For policymakers, coffee‐ and corn‐producing municipalities face rising exposure to price volatility as global integration deepens, requiring targeted risk mitigation. Conversely, the weak relationships for soybeans and sugar suggest these sectors may offer more stable foundations for export‐oriented development.\n"]