Unraveling Reduces the Scope of an Entry Level Labor Market: Gastroenterology With and Without a Centralized Match
From 1986 through 1997 the entry-level market for American gastroenterologists was organized by a centralized clearinghouse. Before, and since, it has been conducted via a decentralized market in which appointment dates have unraveled to well over a year before the start of employment. The career paths of gastroenterologists therefore offer a unique opportunity to examine the difference between the market when appointments are decentralized and early, versus when they are made later via a centralized clearinghouse. (Most centralized clearinghouses remain in use once established, and so there is no way to separate changes due to the clearinghouse from other changes that may have taken place over time.) We find that, both before and after the years in which the centralized clearinghouse was used, gastroenterologists are less mobile, and more likely to be employed at the same hospital in which they were internal medicine residents, than when the clearinghouse was in use. This suggests that the clearinghouse serves not only to coordinate the timing of appointments, but that it also increases the scope of the market, compared to decentralized markets with early appointments and exploding offers. This has implications for theories of market failure due to unraveling over time.
Niederle, Muriel and Alvin E. Roth. "Unraveling Reduces Mobility In A Labor Market: Gastroenterology With And Without A Centralized Match," Journal of Political Economy, 2003, v111(6,Dec), 1342-1352.