[en] This paper examines the implications of alternative forms of cap-and-trade regulations on the California electricity market. Specific focus is given to the implementation of a downstream form of regulation known as the first-deliverer policy. Under this policy, importers (i.e., first-deliverers) of electricity into California are responsible for the emissions associated with the power plants from which the power originated, even if those plants are physically located outside of California. We find that, absent strict non-economic barriers to changing import patterns, such policies are extremely vulnerable to reshuffling of import resources. The net impact implies that the first-deliverer policies will be only marginally more effective than a conventional source-based regulation. - Highlights: • We model the effectiveness of rules designed to regulate the carbon content of electricity imports under California's carbon cap-and-trade system. • We construct a simulation of the electricity market in the Western U.S. based upon actual 2007 market data. • We perturb the market model with variations of cap-and-trade designs. • We find that current policy will lead to substantial “reshuffling” of emissions and limit the impact of California's emissions cap