Efficiency wage hypothesis

In labor economics, the efficiency wage hypothesis argues that wages, at least in some markets, form in a way that is not market-clearing. Specifically, it points to the incentive for managers to pay their employees more than the market-clearing wage in order to increase their productivity or efficiency, or reduce costs associated with turnover, in industries where the costs of replacing labor are high. This increased labor productivity and/or decreased costs pay for the higher wages.

Because workers are paid more than the equilibrium wage, there may be unemployment. Efficiency wages offer, therefore, a market failure explanation of unemployment, in contrast to theories that emphasize government intervention (such as minimum wages). However, efficiency wages do not necessarily imply unemployment, but only uncleared markets and job rationing in those markets. There may be full employment in the economy, and yet efficiency wages may prevail in some occupations. In this case there will be excess supply for those occupations, but some applicants are not hired and have to work for a probably lower wage elsewhere.

The term "efficiency-wages" (or rather "efficiency-earnings") has been introduced by Alfred Marshall to denote the wage per efficiency unit of labor. Marshallian efficiency wages would make employers pay different wages to workers who are of different efficiency, such that the employer would be indifferent between more efficient workers and less efficient workers. The modern use of the term is quite different and refers to the idea that higher wages may increase the efficiency of the workers by various channels, making it worthwhile for the employers to offer wages that exceed a market-clearing level.

There are several theories (or "microfoundations") of why managers pay efficiency wages (wages above the market clearing rate):

The model of efficiency wages, largely based on shirking, developed by Carl Shapiro and Joseph E. Stiglitz has been particularly influential.

The shirking model begins with the fact that complete contracts rarely (or never) exist in the real world. This implies that both parties to the contract have some discretion, but frequently, due to monitoring problems, it is the employee’s side of the bargain which is subject to the most discretion. (Methods such as piece rates are often impracticable because monitoring is too costly or inaccurate; or they may be based on measures too imperfectly verifiable by workers, creating a moral hazard problem on the employer’s side.) Thus the payment of a wage in excess of market-clearing may provide employees with cost-effective incentives to work rather than shirk. In the Shapiro and Stiglitz model, workers either work or shirk, and if they shirk they have a certain probability of being caught, with the penalty of being fired.Equilibrium then entails unemployment, because in order to create an opportunity cost to shirking, firms try to raise their wages above the market average (so that sacked workers face a probabilistic loss). But since all firms do this the market wage itself is pushed up, and the result is that wages are raised above market-clearing, creating involuntary unemployment. This creates a low, or no income alternative which makes job loss costly, and serves as a worker discipline device. Unemployed workers cannot bid for jobs by offering to work at lower wages, since if hired, it would be in the worker’s interest to shirk on the job, and he has no credible way of promising not to do so. Shapiro and Stiglitz point out that their assumption that workers are identical (e.g. there is no stigma to having been fired) is a strong one – in practice reputation can work as an additional disciplining device.

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