We study the repeated implementation of social choice functions in environments with complete information and changing preferences. We de?ne dynamic mono- tonicity, a natural but nontrivial dynamic extension of Maskin monotonicity, and show that it is necessary and almost suf?cient for repeated...

We prove that a social choice function is repeatedly implementable if and only if it is dynamically monotonic when the number of agents is at least three. We show how to test dynamic monotonicity by building an associated repeated game. It follows that a weaker version of Maskin monotonicity is...

We present a new and simple mechanism for repeated public good environments. In the Conditional Contribution Mechanism (CCM), agents send two message of the form, "I am willing to contribute x units to the public good if in total y units are contributed." This mechanism offers agents risk-free...

This paper studies repeated implementation of social choice functions in environments with complete information and changing preferences. We introduce the condition of dynamic monotonicity and show that it is necessary for repeated implementation in finite as well as infinite horizon problems....

The Conditional Contribution Mechanism for public good provision gives all agents the possibility to condition their contribution on the total level of contribution provided by all agents. In this experimental study the mechanism's performance is compared to the performance of the Voluntary...

We analyze the extent to which efficient trade is possible in an ongoing relationship between impatient agents with hidden valuations (i.i.d. over time), restricting attention to equilibria that satisfy ex post incentive constraints in each period. With ex ante budget balance, efficient trade...