Cross-national comparison of policies is basically linked, albeit implicitly, to translation for two main reasons. On the one hand, understanding policies from a comparative point of view is impossible without taking seriously the central role played by language in any political activity. On the other hand, social science research is bound to remain a limited exercise if it postulates that language has no consequences on its very object. These assumptions are explored in the area of cross-national comparison of social policies. Reforms that were conducted for the last ten years on both sides of the Atlantic, under the label of "workfare" and of "activation of social protection" are a case in point. Exploring these reforms while bearing in mind the importance of their linguistic form and the meanings involved in their political construction, negotiation and discussion leads to stressing the importance of political cultures, a topic often underestimated by mainstream cross-national comparison of social protection and labour markets.Cross-national comparison, workfare, activation policies, translation and methods, foreign languages.