Europeans work much less than Americans. Some studies claim this is due to Europe's high taxes and that Europeans would gain by adopting US tax rates and work time. I argue that Americans would gain by reducing work time to Europe's level. Due to historical experience, Europe is able to internalise work‐time‐related negative externalities by enacting restrictive work‐time policies, while the United States is not, resulting in a prisoner's dilemma equilibrium and “overworking trap.” A simple model and work‐time data are used to derive the US welfare gain from reducing work time to Europe's level. Findings are as follows: (i) parameter values are consistent with experimental results on own vs. other people's income value; (ii) the welfare gain's present value is between 80 and 120% of annual welfare; and (iii) a European policy that reduces work time excessively remains beneficial if the reduction is less than twice the optimal one.