School of Economics and Finance

No. 613: Information Sales and Insider Trading with Long-lived Information

Giovanni Cespa , Queen Mary, University of London

October 1, 2007

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Fundamental information resembles in many respects a durable good. Hence, the effects of its incorporation into stock prices depend on who is the agent controlling its flow. Like a durable goods monopolist, a monopolistic analyst selling information intertemporally competes against herself. This forces her to partially relinquish control over the information flow to traders. Conversely, an insider solves the intertemporal competition problem through vertical integration, thus exerting tighter control over the information flow. Comparing market patterns I show that a dynamic market where information is provided by an analyst is thicker and more informative than one where an insider trades.

J.E.L classification codes: G100, G120, G140, L120

Keywords:Information sales, Analysts, Insider trading, Durable goods monopolist