Trade WTA Source

From QED

Source of Trade Data

Introduction

Trade data included in the Mapping Globalization database originates from the World Trade Analyzer (WTA), a data and software product from the International Trade Division of Statistics Canada and available by subscription. The WTA database allows access to information on 600 commodity groups for 192 countries for up to 18 years (1985-2002). For the current Mapping Globalization database, data were downloaded from the WTA on April 6, 2005.

First, countries report their import and export revenues to the United Nations. The UN Statistics Division compiles the Commodity Trade Statistics Database (UN Comtrade). Then Statistics Canada performs a series of data cleaning tasks on the UN data, resulting in adjusted and more consistent data available via the WTA. The cleaning process begins with the exports as the base data, then missing values are estimated through mirror statistics, and wherever possible, the highly aggregated regions or commodity categories are distributed to more detailed countries or categories. Also, Statistics Canada may “roll up” certain territories to be included in the counts of larger countries. (Due to roll up, it may appear that a country exports to itself. For a list of areas with these apparent internal exports, please see Export Anomalies.)

Years of Trade Data

The Mapping Globalization Database includes trade data for the years 1980, 1990 and 2001. The number of countries actually reporting data varies from year to year due to boundary changes, e.g. USSR or Yugoslavia. The WTA data downloads all country/area listings, regardless if that country existed in that year (e.g. USSR) or if the country/area contains any data (e.g. Former Yemen or Other South America East Coast).

Data File Format and Access

All the processes performed by Statistics Canada result in square matrices of every country reporting exports to every other country. This is distributed online though the WTA. While reformatting and data cleaning was performed as part of the Mapping Globalization project, all estimation was done by the UN and Statistics Canada prior to downloading. The data are downloaded in square (e.g. 213 x 213) comma delimited matrices.