Given large numbers of buyers and sellers, with access to a wide variety of information, economic theory suggests that online auction markets should provide an efficient mechanism for establishing equilibrium prices. Previous research on online auction prices, however, is far from conclusive, having produced mixed findings. The seemingly inconsistent and sometimes contradictory results make it very difficult to integrate empirical findings into a coherent body of knowledge. The purpose of this paper is to present a framework that can reconcile previous findings and provide direction for future research. Accordingly, we propose a simple theoretical framework with two dimensions-market structure (thick vs. thin) and quality uncertainty (high vs. low). By examining the literature in the context of market structure and quality uncertainty we find that previous studies are not necessarily at odds, but that there is actually a fairly consistent pattern of results.