In this study, PRISMA'98 -EIM's model for medium-term forecasting, policy analysis and scenario-building- is presented. PRISMA'98 is a macro-sectoral model of the Dutch economy; special feature of the model if the disaggregation of sectors of industry into groups of enterprises of different size.

In this report Appelbaum's model is discussed in detail. The model is also applied to the Dutch construction sector, allowing the degree of collusion to be ascertained. The model consists of five equations. One equation, the mark-up equation, is derived from the assumption of profit maximization...