Thursday, October 15, 2009

Data Manipulation vs. Model Equations

In some Policy Evaluation models the ratio between lines of code (loc) doing data manipulation vs. loc implementing model equations can be surprisingly large. For these models it helps that GAMS has excellent facilities for doing data manipulations (the most important is probably the DISPLAY statement). Here is some numerical evidence:

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These are all GAMS models. The Impact2000 model has actually no SOLVE statement, i.e. it is only data manipulation.