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Integrated Tariff Analysis System (ITAS)

Frequently Asked Questions - Deriving New Results

I want to re-run ITAS to get a full set of results - what do I need to do this?

Users require appropriate hardware and licensed software to run ITAS. The current implementation of ITAS was run using SAS base (version 8) and MS Excel 2002 under Windows XP on a Pentium 4-2400Mhz with 1 Gb of RAM.

There are two steps required to re-run ITAS:

  1. create a directory C:\ITAS on C drive and copy contents of the CD-ROM into this directory. Filenames and paths are used extensively in the SAS programs and care should be taken if the user wants to change these references.
  2. run the batch file COMBB.BAT.

A full set of results for the import tariff module, market access module, price module, tariff revenue module and economic modelling input module is generated in approximately three hours. To re-run the master data preparation module adds approximately one hour to the processing time on the specified machine.

I want to change the formulas - where and how do I do this?

Ten formulas are implemented in the following four programs: (see Footnote i)

  • MERMAC1B.SAS applies five variations of the Girard formula to the tariff schedule of each country (excluding Bangladesh);
  • MERMAC3B.SAS applies three variations of the Chinese formula and two variations of the Swiss formula to the tariff schedule of each country (excluding Bangladesh);
  • MERBGD1B.SAS applies five variations of the Girard formula to the Bangladesh tariff schedule; and
  • MERBGD3B.SAS applies three variations of the Chinese formula and two variations of the Swiss formula to the Bangladesh tariff schedule.

To change the formulas, these programs should be modified in the appropriate places and the system then re-run using the batch file COMBB.BAT. For example, to change from a Swiss8 to Swiss10 formula for Bangladesh we find the existing code in the SAS program and modify the parameter value to get new SAS code for Swiss10 (table 1). Changing parameter values in formulas in ITAS is relatively simple and probably does not even require a specialised SAS programmer.

Table 1 Example code for changing a formula Swiss8 to Swiss10 for Bangladesh (a)

Existing code for Swiss8Replacement code (Swiss10)
/* Swiss 8 */
if tu_bound ne . then
tu_bnd4 = (tu_bound*8) / (tu_bound+8) ;
else tu_bnd4 = . ;
/* Swiss 10 */
if tu_bound ne . then
tu_bnd4 = (tu_bound*10) / (tu_bound+10) ;
else tu_bnd4 = . ;

(a) For all other countries the same code must be changed in file MERMAC3B.SAS. Further, similar code implements formulas on trade-weighted HS6 tariffs and must also be changed.
Source: ITAS program MERBGD3B.SAS.

For other countries, similar changes are required to implement formulas on both unweighted and trade-weighted tariffs (for subsequent analysis using an economic model, such as GTAP).

I want to see the effects of a new formula - how can I do this without using SAS?

A set of MS Excel files containing initial bound and applied rates for each HS6 product and trading partner are generated by ITAS to allow users to apply other formulas to these initial rates in Excel. These Excel files are called XXXBL.XLS, where XXX refers to the abbreviation for each country (see table A.2) and are found in the \ITAS\Utilities\Excel_data directory.

However, some of these Excel files are very large and make this method of calculating final rates slow, cumbersome and likely to result in user-errors. (see Footnote ii) Users would also have to do any subsequent aggregation/averaging of final rates for their analysis.

I want to add an importing country - how do I do it?

Programs in the master data preparation module convert the WTO source data into the format used in the final database in ITAS. Variations in the basic processing structure between countries are shown in appendix D (figures D.3 to D.8). There are three main steps to add an importing country: acquiring WTO data; adding a series of SAS programs for the new country to the master data preparation module; and including the new country in each program in the analysis modules.

Source data

Source data in text file format are located in the IDB File Transfer Facility on the WTO members website ( CTS and IDB data for a country may be downloaded by the following categories of authorised users:

  • all WTO Members;
  • Acceding countries or territories that have provided IDB submissions;
  • the WTO secretariat;
  • the following intergovernmental organisations: Caribbean Regional Negotiating Machinery; Caribbean Community Secretariat (CARICOM); Food and Agricultural Organisation; International Monetary Fund; International Textiles and Clothing Bureau; International Trade Center; Organisation for Economic Co-operation and Development; United Nations Conference on Trade and Development; United Nations Economic and Social Commission for Asia and the Pacific; and the World Bank.

Other intergovernmental organisations require prior approval by the WTO Committee on Market Access to gain access to the data.

SAS programming

Appendix D shows how the source data from the WTO and programming required to create a consistent database can vary considerably. Rather than set up from scratch a new system of SAS programs to create an initial database, it is easier to find an existing processing sequence that provides the closest match to the required processing, make a copy and modify it to process data for the new country (by changing country name references, for example).

Once a consistent initial database has been constructed, most of the subsequent programs in the sequence need to be modified to read and process the files for the additional country.

I want to use twice the MFN rate for unbound items for all formulas - how do I do this?

Most scenarios use the MFN rate for unbound items. However, the current implementation of ITAS uses twice the MFN rate for unbound items in the Girard1c scenario. This treatment of unbound items can be extended to the other formulas as follows.

For unweighted tariff analysis, variable tu_bound uses the MFN rate for unbound items and tu_bnd_g uses twice the MFN rate for unbound items. (see Footnote iii) The treatment of unbound items is changed by substituting the corresponding variables that appear in each formula in programs MERMAC1B.SAS, MERMAC3B.SAS, MERBGD1B.SAS and MERBGD3B.SAS. (see Footnote iv)

I want to analyse tariffs on the exports from Thailand - how would I do this?

The market access module is currently set up to examine the tariffs on Australian exports. Three main programs extract the data for exports: AUSX_DBC.SAS; AUSX_DB.SAS; and AUSX_DBZ.SAS (see figure D.10 in appendix D).

These programs currently read the final data file for each country except Australia and extract data for which the export partner is Australia, thereby generating a consolidated file for Australian exports to the remaining 18 countries in ITAS.

A file containing trade and tariff data for Thailand's exports can be created by amending these programs to read the final data file for each country except Thailand and extracting data for which Thailand is the exporting partner. If the output files (AUSEXPC.SD2, AUSEXP.SD2 and AUSEXPZ.SD2) are not renamed then the remaining programs in the market access module may be re-run (and Australian market access information will be overwritten with that for Thailand).

I want to use the Flexible Swiss formula but target a different maximum bound rate - how would I do this?

The Flexible Swiss 'solver' contains detailed instructions on how to gather the required data and use the solver function in MS Excel to calculate the a and b parameters for the Flexible Swiss formula.

In general, the process is as follows:

  • Paste data for a country into the spreadsheet.
  • Ensure all formulas cover the entire data range.
  • Re-set the a and b parameters to 8 and 1 to verify that you have correctly re-generated the Swiss 8 results (that is, to check the formulas are working).
  • Specify the new target maximum for the (observed) final tariff.
  • Run the solver.
  • Examine the results (some results may not be feasible in light of the way the Flexible Swiss formula effectively 'pivots' the final tariffs from the Swiss formula).

After the Flexible Swiss parameter values have been calculated, these values are manually entered into the MERMAC3B.SAS program and the Flexible Swiss formula activated.


(i) Table 3.1 lists the formulas and appendix B details how each works.

(ii) For example, for the EU there are more than 150,000 records across three Excel worksheets.

(iii) For weighted tariff analysis, t_bound uses the MFN rate and t_bnd_g uses twice the MFN rate for unbound items.

(iv) Other treatments of unbound items can be included by changing the way the initial bound rate tu_bnd_g (and t_bnd_g) is calculated or by generating additional variables for the initial bound rate. These variables are created in files MERBADE.SAS and MECXXX3B.SAS, where XXX refers to the abbreviation for each country (see table A.2).