The paper presents an overview of small-business economics. Small businesses are shown to comprise a substantial and expanding segment of the U.S. economy. The role of small businesses in the economy is considered from the standpoint of various economic theories of the size distribution of firms. Firm-size related empirical regularities are reviewed and their implications for economic theory is discussed. Several small-business policy issues are discussed, including the role of small businesses in labor, macroeconomic, and regulatory policies, along with a review of research on small-business economics that might help guide these policies.