The Linking of Collective Decisions and Efficiency

For groups that must make several decisions of similar form, we define a simple and general mechanism that is designed to promote social efficiency. The mechanism links the various decisions by forcing agents to budget their representations of preferences so that the frequency of preferences across problems conforms to the underlying distribution of preferences. We show that as the mechanism operates over a growing number decisions, the welfare costs of incentive constraints completely disappear. In addition, as the number of decisions being linked grows, a truthful strategy is increasingly successful and secures the efficient utility level for an agent.