This paper presents a dynamic general equilibrium model where labor effort is imperfectly observable and there is unemployment in equilibrium. In contrast to shirking models in the efficiency wage literature, detected shirkers are not dismissed. Instead, they face a monetary punishment because they forgo an increase in their compensation. Estimated versions of the model can generate the high variation in employment and low variation of real wages observed over the business cycle, and are consistent with existing qualitative evidence about the responses of the economy to fiscal policy shocks.