Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Stigler. 1971. The theory of economic regulation. Bell Journal of Economics and Management Science 2 (spring): 3-21.
Stigler uses a simple model of regulation: A regulator (Congress, an agency, or whatever) faces special interest pressure from producers and electoral pressure from consumers. The special interest pressure is always more "persuasive," so producers always win. Regulations are passed only for the benefit of large firms, not for the benefit or protection of consumers.
This doesn't mean that regulators will be blatant about this. There are two ways to help a producer: Via a direct subsidy or via protectionism. Subsidies aren't good--they encourage new entrants into the market, so producers gain only a short-term benefit. Protectionism, on the other hand, limits entry into the market--regulators favor this method. So we see protective regulations like tariffs, occupational licensing, fees, and so on.
Stigler proceeds from two primary premises:
Invariably, large firms win. The logic is Olsonian:
Capture theory (or Congressional abdication theory) says that the industry captures all the rents, and it neglects any supply-side (i.e. regulator) role. Stigler doesn't pay as much attention as he could to supply (see comments below), but does pay enough to show that regulators capture some of the gains.
Stigler looks only at the demand for regulation (demand by producers and consumers), large ignoring the supply-side calculus--that is, he ignores the regulator's motivations. He does touch on the supply-side slightly, pointing out that legislatures want political support, campaign contributions, future employment, bribes, and so on. But by underemphasizing the supply side, he ends with an unrealistic conclusion that consumers always lose. Peltzman's (1976) modification of Stigler's model corrects this problem, resulting in far more realistic predictions.
Stigler also treats the "regulator" as a black box. Later research has unpacked this black box into Congress, bureaucratic agencies, the president, and so on, showing that interactions within this "regulator" might be just as important as the relationships Stigler emphasizes.
Research on similar subjects