Much corruption arises from institutional designs in the public sector that give officials, on the one hand, and private individuals and firms, on the other, incentives to benefit through illegal quid pro quo deals. I will concentrate on how the structure of government programs and the organization of political life create incentives for self-dealing. The criminal law provides a background, but some actions commonly labeled as “corrupt” are not illegal in all polities, and I will discuss the implications of drawing the legal line. I will discuss both market-like situations with many “buyers” and “sellers” of corrupt services, e.g., police work, building inspections, customs, and one-of-a-kind deals for large infrastructure projects, military equipment, etc. Recent attempts to measure corruption and its effects ranges from cross-country indices to lab and field experiments. These can help inform reform projects that stress both the redesign of programs to limit economic rents and efforts to make government more open and transparent so that citizens, the media, and watchdog groups can hold it to account.