Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper estimates the importance of network effects in the market for Yellow Pages. I estimate three simultaneous equations: consumer demand for usage of a directory, advertiser demand for advertising and a publisher's first-order condition (derived from profit-maximizing behaviour). Estimation shows that advertisers value consumer usage and that consumers value advertising, implying a network effect. I find that internalizing network effects would significantly increase surplus. As an application, I consider whether the market benefits from monopoly (which takes advantage of network effects) or oligopoly (which reduces market power). I find that a more competitive market is preferable. Copyright 2004, Wiley-Blackwell.