The "HERMES" European system of models is featured in this book. This system was set up at the initiative of the Commission of the European Communities (Directorate-General for Science, Research and Development). It involves a series of medium term, macrosectoral econometric models in which energy plays a special role as a production factor. The different models are interlinked by a bilateral flow module, which describes for each product the trade between all the Community countries taken in twos. The United States, Japan and five zones are represented in this by simplified versions of the Commission's COMET model.This volume will help the reader to understand and interpret the numerous studies which have been undertaken with the help of the HERMES system. Economists and researchers will find valuable information and figures, with a common nomenclature, on the economies of the different countries, both on structural data and on economic operators.