This paper is devoted to an old question, but one drawing sharply renewed interest: productivity in relation to public services. Public services are a particularly difficult challenge for productivity assessment (its definition, evaluation, as well as strategic implementation), insofar as they add to the traditional difficulties introduced by the service dimension of the output, and other difficulties related to its public (or non-market) dimension. This report aims to take these analytical difficulties into account, along with a certain number of measuring experiments (traditional index methods, frontier techniques). It also highlights the advantage of more critical alternate frameworks, which question the relevance of the productivity concept.