We examine two key channels through which commodity price super-cycles affect the economy: a wealth channel, through which higher commodity prices increase domestic demand, and a cost channel, through which they induce wage increases. By exploiting regional variation in exposure to commodity price shocks and administrative firm-level data from Brazil, we empirically disentangle these transmission channels. We introduce a dynamic model with heterogeneous firms and workers to further quantify the mechanisms and evaluate welfare. A counterfactual economy in which commodity booms are purely endowment shocks experiences only 30% of the intersectoral labor reallocation between tradables and nontradables, and 40% of the within-tradables labor reallocation between domestic and exported production. Finally, the consumption-equivalent welfare gain of a commodity super-cycle is twice as large in the counterfactual economy.