Why a fixed workweek? ∗ Antonia Dı́az†

The main goal of this article is to to explain why the fixed workweek appeared. To this purpose we differentiate between “jobs ” and “hours per job”. We consider an economy where hours and number of workers are substitutes in production but in which hiring a worker entails a fixed cost plus a variable cost per hour worked. This fixed cost implies that, for firms, it is not equivalent to hire a worker for eight hours or eight workers for an hour. Therefore, firms would like workers to work as many hours as physically possible. In an unregulated economy, workers work more hours that they would like to at the on-going wage rate. This situation characterizes the economy of today’s industrialized countries in the XIXth century