Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We provide a model in which an intermediary can choose between wholesale or agency. The possibility that buyers and sellers transact directly limits his market power and, thus, creates incentives for him to deter the emergence of bilateral exchanges. In equilibrium, the intermediary chooses agency and thereby pre-empts the emergence of a competing bilateral exchange if the matching technology of the competing exchange is sufficiently efficient. For symmetric Pareto distributions, whenever agency is chosen in equilibrium, consumer and social surplus decrease while listing and transaction prices tend to increase. The predictions of our model are broadly consistent with empirical evidence.