County-level income inequality and suicide in the United States

We introduce a new county-level panel of annual U.S. income inequality measures for 2010-2021 and make the dataset publicly available with planned annual updates. The panel harmonizes upper-tail indicators (e.g., Top 10%, Top 5%, and Top 1% income shares) with full-distribution indices, enabling comparisons that standard sources do not permit. The panel provides the first county-level estimates of top income shares, previously unavailable for the United States. Linking these measures to suicide mortality and rich covariates, we find that higher upper-tail income concentration is associated with higher suicide mortality in nonmetropolitan and micropolitan counties, whereas distribution-wide indices (e.g., the Gini) exhibit weaker or null associations. A proxy for firearm availability is positively related to suicide rates, and the uninsured rate is a significant risk factor even after controlling for earnings, unemployment, population scale, and demographics. Results are robust to alternative population weights, clustering, lags, rural-urban definitions, and expanded control sets.