State Building in Boom Times argues that commodity booms and coalitional politics are central to understanding the state building variation within and across Latin America and Africa. It shows how resource booms can trigger the provision of new public goods and institutional strengthening and thus help countries expand their state capacity. But these possibilities hinge on coalitional politics, as seen through six cases. Countries ruled by export-oriented coalitions (Argentina, Chile, and Mauritius) expanded their state capacity as a direct result of commodity booms. But countries in which exporters were politically marginalized (Colombia, Ghana, and Nigeria) missed analogous state building opportunities because ruling coalitions preyed upon export wealth, rather than promoting export interests via state building. The coalitional basis of these divergent outcomes suggests that, contrary to the prevailing belief in a resource curse, natural resource wealth does not necessarily dispose countries to low state capacity. Instead, export-oriented coalitions can harness boom times for developmental gains, even in the context of weak institutions. This finding warrants reappraising some widespread presumptions about the relationship between resource wealth and state building, as well as the public policies that are commonly proposed for developing countries to manage their natural resource wealth.