Private provision of public goods in a second-best world: Cap-and-trade schemes limit green consumerism

Private provision of public goods can only supplement government provision if individual actions affect the level of the public good. Cap-and-trade schemes reduce the overuse of common resources such as a stable climate or fish stocks by imposing a binding cap on total use by regulated agents. Any private contributions provided by means of e.g. green consumerism or life-style choices within such a scheme only impacts on who uses the resource but leaves total use unaffected. Perfect offsetting of marginal contributions is a key design element of cap-and-trade schemes. As real world cap-and-trade policies like the EU Emission Trading System have incomplete coverage, understanding what they cover is crucial for individuals aiming to contribute. Otherwise contribution efforts backfire.