Multi-attribute reverse auctions and negotiations with verifiable and not-verifiable offers

Comparative studies of auction and negotiation exchange mechanisms have typically compared the outcomes obtained from the two mechanisms. Their result are inconclusive. The question which this paper aims to address is the viability of outcome-based comparisons. Such comparisons assume that both mechanisms produce the same types of outcomes but their values differ. An argument can be made that this is not necessarily the case. Based on several experiments of multi-attribute auctions and two formats of multi-bilateral negotiations the paper argues that the two mechanisms produce some outcomes which are comparable and other outcomes which are qualitatively different. A surprising finding of our experiments is that the outcomes of the non-verifiable negotiations were more similar to the outcomes of the reverse auctions than to the verifiable negotiations, despite the fact that the latter employ rules taken from the auction mechanism.