Input-output model ISIS

4 Input-output model ISIS 18.4.1 General modelling approach 

The main elements of the used input output model ISIS are described in the following. At the core of ISIS is a statistical input output model (IO model) used to examine the structural impacts of the various strategies. Other modules for employment effects, qualification structure and job conditions, regional effects and environmental effects were developed or added to analyse other dimensions of sustainability. The results of the scenario calculations from the IO model, i.e., production changes as a result of the different strategies, serve as inputs for the other modules. 

The IO model used for ISIS is based on the most recent input output tables of the European Statistical Office (Eurostat, 2004) for the year 2000. It can be assigned to 

Interrelation matrix supplies of goods and services among the sectors (intermediate demand) (millions of euros) 

Assuming that a linear approximation can be made for the correlation between the sectoral employment level and the sectoral production level, the quantitative impacts on employment are calculated using job coefficients. Of course, the constant input-output coefficients are a strong assumption and could be criticised (Zhang and Folmer, 1998). However, structural effects could be analysed in a ceteris-paribus analysis with the chosen approach. 

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