International Merchandise Trade Price Index (IMTPI)

Detailed information for March 2024





Record number:


Purpose: To provide statistical information and analysis of the price and volume of Canada's merchandise exports and imports by commodity on a customs-basis and a balance of payments-basis.

Data release - May 2, 2024


The International Merchandise Trade Price Index (IMTPI) is an indicator of the changes in import and export prices. The IMTPI measures price change by comparing, through time, the weighted average cost of a basket of traded commodities. The price indexes are based in part on actual unit values processed by the International Accounts and Trade Division (IATD) and, where unit values are unavailable or too volatile, by the use of price relatives provided by other sources. Price indexes are subsequently used to deflate current dollar values and produce statistics on import and export volumes.

Statistical activity

This activity is part of the Canadian International Merchandise Trade (CIMT) Program. The objective of this statistical program is to provide measures of Canada's international merchandise trade through the production of import and export statistics.

Canadian trade statistics are compiled according to the "general" system of trade as defined by the United Nations Statistical Office. The general trade system is in use when the statistical territory of a country coincides with its economic territory. Consequently, under the general trade system, imports are recorded when goods enter the economic territory of a compiling country, and exports when goods leave the economic territory of a compiling country.

The closing of the statistical month for imports and exports is defined as the last calendar day of the month based on the date of clearance from Customs. Documents received too late for incorporation in the current month are assigned to the month the transaction took place and are published as revisions the following statistical month.

Additional information about the CIMT Program is available through the link that follows.

Reference period: Month

Collection period: Every month


  • Balance of international payments
  • Economic accounts
  • International merchandise trade price indexes
  • International trade
  • Merchandise exports
  • Merchandise imports
  • Prices and price indexes

Data sources and methodology

Target population

Fixed (Laspeyres) and current (Paasche) weighted price indexes as well as volume measures are calculated monthly, quarterly and annually for Canadian merchandise imports and exports.

Instrument design

This methodology does not apply.


The International Merchandise Trade Price Index (IMTPI) is a composite price index designed to express, in a single index, price changes that involve a range of commodities. In order to accurately reflect the realities of the price movement, a fixed basket of goods is chosen which is representative and correlated to the rest of the commodities in the trade universe. All commodities in the basket have been divided into groups where criteria, such as value, were used to select the most significant ones.

The indexes are based on a non-random sample of import and export commodity classes for which either a meaningful unit value can be calculated or for which a representative proxy index can be found.

Data sources

Data are extracted from administrative files and derived from other Statistics Canada surveys and/or other sources.

Data are collected from the CIMT Program (both customs and balance of payments), from the International Product Price Index Program, and from external data sources.

International trade price and volume indexes for all countries are constructed from detailed import and export merchandise trade data. Price inputs for these indices originate from two sources: unit values derived from the detailed customs-basis data and specific price indexes taken from Canadian and foreign sources.

Several organizations provide the CIMT Program with proxies that are used as price relatives in the calculation of the Laspeyres and Paasche price indexes. They are:

- The United States Bureau of Labor Statistics publishes the Producer Price Index (PPI) which measures the average change over time in the selling prices received by US producers for their output. The PPI includes indexes at various levels of aggregation and is used primarily to calculate a number of the CIMT Program's import price indexes.

- Statistics Canada's Producer Prices Division (PPD) publishes the Industrial Product Price Index (IPPI) (Record number 2318) which measures price changes for major commodities sold by manufacturers in Canada. Most of the specified price indexes taken from the IPPI are used to calculate the CIMT Program's export price indexes.

- PPD publishes the Computer and Peripheral Price Index (CPPI) (Record number 5032) which measures changes in the price of computers and computer peripherals sold to governments, businesses and consumers. It is used by the CIMT Program primarily to measure price changes in imports of computer parts.

- PPD also publishes the Export Import Price Index (Record number 5142) which is a survey that measures price changes for key commodities that have proven difficult to measure through other methods.

- The Bank of Japan publishes the Corporate Goods Price Index (CGPI) which measures price changes for goods traded in the Japanese corporate sector. The CIMT Program uses the Export Price Index component of the CGPI to measure Canada's import prices for goods imported from Asian countries.

- The Canada Energy Regulator provides price data on electricity and crude petroleum, and the Canadian Centre for Energy Information of Statistics Canada provides data on exports of crude petroleum and natural gas.

Error detection

During the calculation of the Laspeyres indexes and Paasche indexes, a module uses a method described by Hidiroglou and Berthelot (1986) to identify outlier observations. Historical trends are also used to identify transactions within an aggregation that are "abnormal" for a given period. The error detection process is only done at the first stage of aggregation in the construction of the International Merchandise Trade Price Index.


If, during the error detection process, a unit value has been identified as an outlier, corrective measures are taken.

For Laspeyres and Paasche price indexes that cannot be calculated due to a lack of transactions or missing proxy information, a valid index from the previous period is automatically carried forward and repeated for the current period. This implies no measurable change in the price for the commodity.


Prices for the commodity group "Special transactions trade" cannot be reliably measured through unit values or proxies, and therefore an estimate is required. A weighted average of the price indexes calculated for all other commodity groups is used to estimate the Laspeyres and Paasche indexes for this group.

A commodity group "Other balance of payments adjustments" exists only for the BOP-basis data. Prices for this category cannot be measured through conventional means, and so an estimate is required. The National Economic Accounts Division (NEAD) provides this estimate to IATD.

For natural gas and electricity exports, estimates are required for prices in the current month for both customs- and balance of payments-basis statistics. Natural gas exports also require an estimate for the previous month for customs-basis statistics, as source data are not available. Balance of payments-basis export statistics for crude oil are also estimated for the current month, as source data from the Canada Energy Regulator are not available at the time of publication.

Price indices are aggregated from Harmonized System (HS) code by Trading Area (TA) level to North American Product Classification System (NAPCS) aggregations (NAPCS Class, NAPCS Group, NAPCS Division, NAPCS Section, NAPCS total) for all representative trade commodities selected in the export/import price basket. Current (Paasche) weighted indices are influenced by changes in the period-to-period constant dollar (K$) value of trade. Fixed (Laspeyres) weighted indices are influenced by changes in the period-to-period price relative movements. Weight shifts can occur with changes in representative current dollar (C$) trade for each level of aggregation.

Quality evaluation

Aggregated data are subject to month-over-month and year-over-year analysis to detect errors and explain observed movements.

The models used to seasonally adjust data are reviewed annually by the Economic Statistics Methods Division of Statistics Canada.

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects which could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.

The CIMT Program of Statistics Canada is similar to the statistical programs of most other countries in its use of administrative data derived from Customs sources to produce merchandise trade data and its use of the 'passive suppression' approach for confidentiality. Passive suppression requires that appropriate measures be taken only at the request of importers or exporters who feel that their interests would be harmed by the dissemination of data. The onus of notifying the CIMT Program of suspected instances of the release of confidential data rests with the affected companies. After receiving and reviewing such requests, data are suppressed, if necessary, to prevent direct or residual disclosure of identifiable data.

Revisions and seasonal adjustment

Merchandise trade data are revised on an ongoing basis for each month of the current year. For customs-basis data, the previous year's data are revised with the release of the January and February reference months as well as on a quarterly basis. The previous two years of customs-basis data are revised annually and are released in February with the December reference month.

For balance of payments-basis data, the previous year's data are revised with the release of the January, February, March and April reference months. To remain consistent with the Canadian System of Macroeconomic Accounts, revisions to balance of payments-basis data for previous years are released annually in December with the October reference month.

Factors influencing revisions include late receipt of import and export documentation, incorrect information on Customs forms, replacement of estimates with actual figures, changes in classification of merchandise based on more current information, and changes to seasonal adjustment factors.

Revised data are available in the appropriate published data tables and statistical products.

Data accuracy

The administrative data used to compile trade statistics are considered to be complete and accurate. Any anomalies or inconsistencies detected are verified with the source and where necessary, adjustments are made to reconcile data with the conceptual framework of the series.

It is not unusual for the accuracy of export statistics to be adversely affected by undercoverage and/or country misallocation. While Statistics Canada does not have a direct measure of undercoverage, a monthly estimated adjustment is included within BOP-basis data. Country misallocation occurs when the country of final destination is inaccurately reported on the Customs documentation. This occurs most frequently when goods are routed through an intermediary country before continuing to their final destination with the intermediary country being reported as the final destination of the goods.


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