Measurement and its uses: Harmonization and quality in social statistics

The European construction has induced a strong demand of harmonization of s tatistics of the various countries. The latter can be focused on an harmoni zation of outputs, already practised for a long time by national accountant s: the statistical variables are defined in common, then each country measu res them according to its own means. On the other hand, the harmonization o f inputs, more ambitious, seeks a standardization of all the construction p rocess and data collection. This leads to distinguish clearly the two momen ts of use and of production of economic and social statistics. Now the same distinction is made in the debates over the notion of quality of statistic s, which contrast the quality of the product with the one of the process. T his quality cannot be judged independently from the expected uses of these statistics and of their form of social credibility. From this point of view , the various harmonization levels are compared with the various forms of c onnection and convertibility between the national currencies.