Changing the economics of RunGTAP -- Overview

This help topic is long and complex. Try maximizing the Help window: you will still need to scroll to

read the whole topic. We suggest that you PRINT the topic from within Help (via right-click).

Then read the printed sheet twice. Later, refer to the printed sheet as you work with RunGTAP.

The specification of the GTAP model and of the tools for interpreting results (such as GTAPView and the welfare decomposition) are contained within a host of ancillary files supplied with RunGTAP. Those files are divided into 8 groups (or modules) each of which contains one TAB file. The files comprising the standard RunGTAP modules are listed in the table below. The files within a single module have the same name, but with different extensions.

Module	TAB file	Other files*
Main model	GTAP.TAB	GTAP.MAP, GTAP.EXP, GTAP.MIN, GTAP.SIN, GTAP.CLG, GTAP.CLP
Shocks	SHOCKS.TAB
GTAPView	GTPVEW.TAB
GTAPVol	GTPVOL.TAB
Welfare Decomp	DECOMP.TAB	DECOMP.MAP
Partial Elasticities	PEELAS.TAB
GE Elasticities	GEELAS.TAB	GEELAS.MAP
Altertax	ALTPAR.TAB

* As well as the files listed, each TAB file requires a STI file, and either GSS and GST files or AXT, AXS, and EXE files. For example, RunGTAP comes with GTAP.STI, GTAP.AXS, GTAP.AXT, and GTAP.EXE for the standard GTAP model. If both GSS/GST and AXT/AXS/EXE files are found, the GSS will be used.

You can specify that RunGTAP will use a different module, if you can supply or have been given the appropriate files. For example, you might create your own improved DECOMP module. You would have to create your own complete set of files perhaps called DECOMPX.TAB, DECOMPX.STI, DECOMPX.AXS, DECOMPX.AXT, DECOMPX.EXE and DECOMPX.MAP. You need to have a recent version of GEMPACK to create these files (recent means version 7.0 or later).

These files could be stored in the main RunGTAP directory. In that case, you could specify that DECOMPX was used either for all versions (aggregations) of the model, or just for specific versions. Or, if DECOMPX is to be used for one version only, you should store the DECOMPX files in that version directory.

RunGTAP also lets you disable any module (except for the main model). This might be especially useful while developing new modules. Possibly, your version of GTAP, GTAPQ, might prevent the original GTPVOL module from running properly. You could switch off GTPVOL for a while, until you had time to create your own GTPVOLZ module which would cooperate with GTAPQ. Again, you can disable a module either globally (for all versions) or locally (for specific versions).

To see an example of model customization, change to the TP14 version which is supplied with RunGTAP. Then choose the menu item Version...Modules. You will see that for this version the GTAP module is replaced by the GTAPTP14 module (which adds monopolistic competition).

Notice that in the examples above, the names of the customized TABLO programs (DECOMPX, GTAPTP14) are all formed by adding letters to the names of the original TABLO programs (DECOMP, GTAP). RunGTAP insists you follow this rule.