Prior to the commencement of the ESEC validation process, the prototype ESEC will first be compared with the UK NS-SEC from which it will be derived. This will be done using especially collected data on employment relations from the 1996/97 UK LFS. This will provide an initial check of the validity of the ESEC derivation matrix based on ISCO-88(COM). A similar study using French data will be undertaken by INSEE at step 4. The prototype ESEC will then be implemented by WARWICK in at least two major sources of harmonised EU data, the European Labour Force Survey (ELFS) and the European Community Household Panel (ECHP). This will give rise to a ‘statistical indicators’ compendium. The compendium will provide a country-by-country comparison of various indicators of socio-economic conditions and health by the categories of the ESEC. All partners will have the opportunity to study these in detail prior to the finalisation of their plans to validate the classification (step 3, work package 4).