Assistance preparing country data for GTAP

NB: This web page is not officially authorized by the Global Trade Analysis Project [GTAP]. For the latest, authoritative, information about the GTAP database construction process, you should consult the official GTAP website.

Production of the GTAP database of world production and trade is coordinated at Purdue. A new database is produced about every two years. Data is contributed by various organizations. To distinguish a country as a separate region within GTAP, the Purdue team requires a recent SU [supply-use] table, IO [input-output] table or SAM [social accounting matrix]. The data must be supplied in a special format. The Purdue team then:

For more information about contributing country data to GTAP, see here. Contact emails are listed at at the end of this page.

Assistance from CoPS

Country-specific SU/IO/SAM data is usually contributed by an organization or individual based in the country concerned. GTAP prefers local contributors, since they help to form a network of database users who have a direct interest in the quality of the data. However, sometimes no local contributor is available, or a contributor cannot easily format the data in the way required by Purdue. In such cases, assistance (especially with the formatting) may be purchased from the Centre of Policy Studies [CoPS]. The client could be an organization wishing to perform GTAP simulations which identify a country not distinguished separately in the current GTAP database. Or the client might wish to extend the GTAP regional coverage for altruistic reasons.

Steps in contributing a country database

The whole process includes:

  1. Collecting SU or IO table or SAM. These are normally provided by the client. SU or IO tables are most used as they often contain more detailed sectors. SAMs contain supplementary information (eg, income distribution) not used directly by GTAP today, but worth collecting for possible future use. It is important to gather also descriptions of what each sector contains, so that the SU/IO table sectors can be mapped to the GTAP sectors.
  2. Trying to work out what the SU/IO table means -- each table has idiosyncratic features.
  3. Translating the SU/IO table to the special format demanded by GTAP at Purdue. The translation is done with a GEMPACK program written in the TABLO language. Each IO table has its own special format, so the program has to be built specially.
  4. Answering queries from Purdue about the data.
  5. Preparing a report about the data sources -- this eventually becomes part of the GTAP data documentation.

Typically, CoPS would be responsible for steps 2 to 5 above.

Purdue cooperation is needed

The addition of bi-lateral trade and protection data for a new GTAP country is a non-trivial task which is done at Purdue. As mentioned above, the GTAP database is updated on a 2-year cycle. "Interim" releases, reflecting bug-fixes or new regions, might appear more frequently. Nevertheless it could be several months before a new contributed region appears in the GTAP database. The Purdue staff may be willing to accelerate the release of a GTAP database which distinguishes a new region. However, the client would need to arrange this with Purdue.

CoPS personnel used

Mark Horridge is the CoPS person most likely to be involved -- he has contributed a number of countries to the GTAP database. However, the CoPS staff includes several others with the necessary skills.


Usually the client is in a hurry to perform GTAP simulations which recognize the new country. In terms of elapsed time, three stages may be distinguished:

  1. Client makes arrangements with CoPS; client collects SU/IO table or SAM.
  2. Data is processed and converted to GTAP format at CoPS, then sent to Purdue.
  3. Purdue incorporates country data into a special version of the GTAP data base, which is sent to client.

Normally stages 1 and 3 take longest. In particular, time taken for stage 3 will depend on how busy the Purdue workers are.


Since CoPS is supported entirely by outside work (mainly consulting for Australian organizations), a labour charge is payable. A typical charge (assuming raw IO data was supplied, no travel) might be $US 10,000. There is some economy in doing several countries as a batch: this might cost $US 10,000 for the first country, and $US 7000 for each additional country. Additional charges would apply if travel was required (see below), and the client would need to reimburse travel costs.

Travel required?

In many cases the CoPS part of the work can be done in Australia and travel is not necessary. It is most likely to be required if:

The raw SU or IO or SAM data

Raw data tables may be sent to CoPS in either spreadsheet or text files. The more sectoral detail, the better. There should also be some descriptive material, including:

For more information, contact .

Purdue data contribution contacts:
Angel Aguiar
GTAP support
General GTAP email address

See also:
CV and personal details for Mark Horridge
GTAP Home Page
CoPS Home Page