This relates to GTAP Technical Paper No. 18:
"Implementing Bilateral Tariff Rate Quotas in GTAP using GEMPACK"
by Aziz Elbehri and Ken Pearson, December 2000, Revised April 2005, Second Revision July 2005.
There were errors in the equations for calculating quota rents in the December 2000 and April 2005 versions of Technical Paper 18 and in the associated TAB files.
These errors are corrected in the July 2005 version of the Technical Paper which you can download [save this as file TP-18.PDF] (410K).
The authors apologise for these errors. We are grateful to Martina Brockmeier and to Carsten Struve who pointed out the errors and indicated how to correct them.
Fortunately these errors had little effect on the results obtained in simulations.
You can find more information about these errors in Appendix 3 (section 11) of the July 2005 version of the Technical Paper.
You can also download corrected versions of the related TAB files which were made available with Release 8.0 (October 2002) of GEMPACK.
We do not supply corrected versions of the various TAB files which were supplied originally in December 2000 to accompany TP-18. These files (which were in zip file TRQ-EX.ZIP) are now rather outdated and have been superseded by the Complementarity statement methods introduced with Release 8.0 of GEMPACK.
In particular, it is no longer necessary to use TRQmate (supplied with GTAP Technical Paper number 18), nor is it necessary to explicitly run the approximate and accurate runs separately. This is all automated with Release 8.0 or later of GEMPACK.
Accompanying the technical paper are hands-on examples.
TRQ examples [save this as file TRQ-EX.ZIP] (400K)
Section 6 of the above Technical Paper has details about these files.
You can run tariff-rate quota applications under RunGTAP - advice here.