market participant doctrine
market-participant doctrine. The principle that, under the Commerce Clause, a state does not discriminate against interstate commerce by acting as a buyer or seller in the market, by operating a proprietary enterprise, or by subsidizing private business. • Under the Dormant Commerce Clause principle, the Commerce Clause — art. I, § 8, cl. 3 of the U.S. Constitution — disallows most state regulation of, or discrimination against, interstate commerce. But if the state is participating in the market instead of regulating it, the Dormant Commerce Clause analysis does not apply, and the state activity will generally stand. See Dormant Commerce Clause under COMMERCE CLAUSE. [Cases: Commerce 56. C.J.S. Commerce §§ 4, 38, 63, 73, 90, 93.]
