"In this paper, we construct a simple model based on heterogeneity in workers' productivity and homogeneity in their working schedules. This simple model can generate unemployment, even if wages adjust instantaneously, firms are perfectly competitive, and firms can perfectly observe workers'...

The proportion of multiple jobholders (moonlighters) is negatively correlated with productivity (wages) in cross-sectional and time series data, but positively correlated with education. We develop a model of the labor market to understand these seemingly contradictory facts. An income effect...