Abstract The employment ‘double dividend hypothesis’ suggests that an appropriately designed fiscal reform, in which emission charges are used to subsidize employers' social security contributions, may realize (at least) two relevant policy goals: a better quality of the environment and, at the same time, an increase in employment levels. This paper uses a newly developed econometric general equilibrium model for the European Union as well as for each member country and presents simulation results up to the year 2010 of the effects of a European carbon tax the revenues from which are recycled to reduce employers' social security contributions. The results show that recycling carbon tax revenues may provide an ‘employment double dividend’ only in the short run.