Knowledge that Transforms

This paper addresses Alvin Roth’s findings of market contracting at times earlier than optimal for market participants, which Roth describes as market “unraveling,” a market failure he proposes to solve by designing centralized buyer‐seller matching programs. This paper shows that, while Roth’s engineering solutions are ingenious, the early contracting phenomena derive from labor market monopsony. Under monopsony, price is unavailable to clear the market; time of contract becomes the currency for working out market forces. Roth’s matching serves to shore up the monopsony and would be unnecessary if the monopsony were removed; a superior solution is to end the monopsony.

In the context of certain dynamic models, it is possible to infer the elasticity of labor supply to the firm from the elasticity of the quit rate with respect to the wage. Using this property, we estimate the average labor supply elasticity to public school districts in Missouri. We leverage the plausibly exogenous variation in prenegotiated district salary schedules to instrument for actual salary. These estimates imply a labor supply elasticity of about 3.7, suggesting that school districts possess significant market power. The presence of monopsony power in this teacher labor market may be partially explained by its institutional features.