How much can employers in low- and middle-income countries suppress wages below marginal productivity? Using plant and customs data from Colombia, we exploit predetermined variation across plants in sales export destinations combined with variation in exchange rates to generate plant-specific shocks to marginal revenue productivity and labor demand. We estimate a firm-level labor supply elasticity of around 2.5, implying that workers produce about 40% more than their wage level. This result is driven by plants that account for a large share of local employment, consistent with an oligopsonistic labor market model.

This paper studies learning among coworkers when incentives change. We use a simple principal-agent model to show that when workers are not fully informed on the global shape of the production function, (1) their effort choice changes over time as information is disclosed and processed and (2) changing incentives can trigger this learning process. We test this prediction using personnel data from an egg production plant in Peru. Exploiting a sudden change in the contract parameters, we find that workers learn from each other over the shape of the production function. This adjustment process is costly for the firm.