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α: calibrated so average coauthorship-adjusted count equals average raw count
We examine the role of a middleman as an expert in markets. A seller's effort determines the quality of the good. Buyers observe neither the seller's effort nor the good's quality. A middleman, after observing a signal about the good's quality, decides whether to purchase it and then to sell it. We show that the presence of a middleman may either reduce or exacerbate the seller's moral hazard problem. We also consider a model with multiple middlemen. We find that the seller's effort is minimized if either the middleman's signal is perfect or the number of middlemen is large.