g. ‘for fun I gambled for

the items presumably preferred by the other player’; ‘Initially I bid according to my preferences but after a while it was more about winning’. The strategy descriptions of the majority of players, however, are best captured by the statement of one player ‘I made choices according to the value of the item’. The bid dynamics we find, replicate findings from previous studies; players reduced their bids over the course of auctions (Gneezy and Smorodinsky, 2006 and Sheremeta and Zhang, 2010), adjust their bids in the direction of competitor (Cason, Sheremeta, & Zhang, 2012), and increase their bids when losing and decrease their bids when winning (Kuhnen & Tymula, 2011). Over and beyond bid dynamics, our findings extend theories of decision driven preference change (Jarcho et al., 2011 and Sharot et al., 2009) by showing selleck compound library that changes in preference

are evoked by interactions between competitors. Surprisingly, winning Veliparib order an auction had differential effects on competitors’ private value estimates. When social information confirmed one’s private value estimate, winning resulted in an increase in private values. When social information indicated a lower item value, however, winning resulted in decreased private values. It is possible that incrementing bids (as in English auctions) might lead to an update of a bidder’s private value of an item. This seems particularly likely when uncertainty about the private value is high, e.g. art auctions, since social information will then receive a strong weight (Henrich and Boyd, 1998, Toelch et al., 2013 and Toelch et al., 2014). Support for this view comes from experiments investigating repeated bidding in one shot auctions. Here, repeated feedback on the common value reduces overbidding, because trial and error learning strengthens the weight given to individual information (Dyer et al., 1989, Garvin and Kagel, 1994, Lugovskyy et al., 2010, Milgrom and Weber, 1982 and Potters et al., 1998). Along the same lines, Org 27569 a reduction of uncertainty by the seller increases the effectiveness of the auction

by reducing overbidding (Goeree & Offerman, 2003). The findings have important implications for understanding bidding behavior in auctions. While competitive arousal (Ku et al., 2005) or the joy of winning respectively fear of losing (Bos et al., 2013 and Delgado et al., 2008) can impact bidding decisions within common value auctions, we show that information derived from competitors’ bids and subsequent auction dynamics sustainably influence private value estimates. These findings suggest that individuals use social information as a proxy for the private value of an item and adjust their own private value estimate accordingly. This use of social information to reduce uncertainty has been demonstrated frequently and shown to be adaptive under a wide range of tasks (Kendal et al., 2009 and Rendell et al.