We analyse two team settings in which one member in a team has stronger incentives to contribute than the others. If contributions constitute a sacrifice for the strong player, the other team members are more inclined to cooperate than if contributions are strictly dominant for the strong player.

Broken Windows: the metaphor has changed New York and Los Angeles. Yet it is far from undisputed whether the broken windows policy was causal for reducing crime. In a series of lab experiments we show that first impressions are indeed causal for cooperativeness in three different institutional...