Too much investment: a problem of coordination failure

This paper shows that coordination failure and contractual incompleteness can lead to socially excessive investment. Firms and workers choose investment levels then enter a stochastic matching process. If investment levels are discrete, then if match frictions are low enough, high investing workers (firms) impose a negative pecuniary externality on any worker (firm) who cuts investment, even by one unit. Specifically, if a worker cuts investment, he subsequently bargains with a firm which has a high outside option due to the fact it can easily match with another high investing worker; this lowers the private net benefit to cutting investment below the social net benefit. A similar argument establishes that over-investment can occur when agents are heterogenous i.e. differ in their cost of investing, even if investments are continuous. Then, over-investment occurs because low-cost investors have a private incentive to invest to shift rent away from high-cost investors. Our model can also explain some recent trends in graduate/non-graduate wage differentials