The pharmaceutical industry accounts for a substantial chunk of the US economy's research and development investments, which have resulted in significant medical breakthroughs. At the same time, the costs of pharmaceutical products continue to rise, as does pressure to adopt direct or indirect controls on pharmaceutical prices. We review the economics literature on the pharmaceutical industry, focusing particularly on its positive and normative implications for the innovation, pricing, and marketing decisions of pharmaceutical firms. We discuss the major achievements of, and persistent gaps in, the literature, along with lessons for policy.