To what extent, if at all, should a just society adopt public policies that regulate and limit the amount of time people work? Attempts to answer this question face a dilemma: Either, we can adopt a laissez-faire view, according to which governments must refrain from imposing working time policies on the labour market. But this view generates a situation in which many citizens experience deep regret about the balance between work and leisure in their lives. Or, we can endorse an (...) interventionist view that advocates government imposition of working time policies. However, such a view appears to be objectionably perfectionist insofar as it imposes on citizens a particular conception of the ideal balance between work and leisure. This article proposes a way out of this dilemma. It shows that the interventionist view can be defended on the anti-perfectionist grounds that this helps address a collective action problem in the labour market – the working time rat race. Employers often use working time as a proxy for their employees’ productivity and commitment. Those who work particularly long hours are often awarded benefits such as raises or promotions or are spared from dismissals. This makes it individually rational for each worker to work extra hours in an attempt to outcompete colleagues. However, if many workers pursue this strategy, it loses its effectiveness. Workers with preferences for more leisure have a claim to state intervention to remove the rat race when this doesn’t impose disproportionate harm on third parties. (shrink)