Indivisibility of labor

In macroeconomics, indivisibility of labor is the idea that labor cannot be used in continuous units but must be purchased from workers in blocks of time, such as eight hours a day or forty hours a week. This model can result in differences in the number of hours worked even though the workers are assumed to be identical: some workers may be unemployed while others are fully employed or even overemployed.

The opposite presumption would be that labor may be purchased in continuous units, that workers are identical, and workers' utility functions as concave in leisure and income. Under this model, an optimal outcome is for all workers to work some of the time: all workers are at least partially employed and none are unemployed.