—Authority flow and proximity search have been used extensively in measuring the association between entities in data graphs, ranging from the Web to relational and XML databases. These two ranking factors have been used and studied separately in the past. In addition to their semantic differences, a key advantage of proximity search is the existence of efficient execution algorithms. In contrast, due to the complexity of calculating the authority flow, current systems only use precomputed authority flows in runtime. This limitation prohibits authority flow to be used more effectively as a ranking factor. In this paper we present a comparative analysis of the two ranking factors. We present an efficient approximation of authority flow based on proximity search. We analytically estimate the approximation error and how this affects the ranking of the results of a query.