Commodity markets are integral to the global economy. Understanding what drives developments of these markets is critical to the design of policy frameworks that facilitate the economic objectives of sustainable growth, inflation stability, poverty reduction, food security, and the mitigation of climate change. This study is the first comprehensive analysis examining market and policy developments for all commodity groups, including energy, metals, and agriculture, over the past century. It finds that, while the quantity of commodities consumed has risen enormously, driven by population and income growth, the relative importance of commodities has shifted over time, as technological innovation created new uses for some materials and facilitated substitution among commodities. The study also shows that commodity markets are heterogeneous in terms of their drivers, price behavior, and macroeconomic impact on emerging markets and developing economies, and that the relationship between economic growth and commodity demand varies widely across countries, depending on their stage of economic development. Policy frameworks that enable countercyclical macroeconomic responses have become increasingly common-and beneficial. Other policy tools have had mixed outcomes.