Extensive experimental research on public goods games documents that many subjects are “conditional cooperators” in that they positively correlate their contributions with (their belief about) contributions of other subjects in their group. The goal of our study is to shed light on what...

Fundraising for public goods by private contributions is often undermined by free-riding. One prominent mechanism suggested to alleviate problem of free-riding is a fixed-prize lottery with winning probabilities proportional to individual contributions (Morgan, 2000; Morgan and Sefton, 2000). Yet,...

This study presents a laboratory experiment of the first and second price sealed bid auctions with independent private values, where the distribution of bidder valuations may be unknown. In our experimental setting, in the first price auction, bids are lower in the presence of ambiguity. This...