Brug af kædeindeks i modelberegninger

We investigate a switch from fixed-weighted national accounts data to chain-type data in the quarterly macroeconometric model Mona. The idea behind this change in the national accounts data is to reduce the substitution bias, which has grown with the amount of high-technology goods with a weak price development deviating from the average. In line with Lasky (1998) we demonstrate that the use of chain-type GDP can also reduce the composition effects, which constitute a standard problem in macroeconometric models based on traditional fixed-weighted data. Chain-type national accounts data are not perfect as e.g. their lack of additivity makes them more complex to work with. We demonstrate that their lack of reversibility may also complicate some model results by leading to permanent effects from temporary chocks. However, the damaging effect of irreversibility is not necessarily dominating so a switch to chain weights may still be interesting.