Handbook of Methods International Price Program Concepts

The U.S. Import and Export Price Indexes (MXPI) measure the average change in the price level over time for goods and services imported to and exported from the United States. Exports are goods and services sold or transferred by U.S. residents to foreign residents. Imports are goods and services that U.S. residents buy or receive from foreign residents. Price indexes and their movements are used to measure the impact of international trade in the U.S. economy. Each price index represents a basket of products of internationally traded goods or services based on commodity or industry groupings. Each item in the basket has specific characteristics and BLS collects prices for these items over time. This matched-item pricing methodology is the basis of price collection. The import and export price indexes are calculated separately.

The U.S. Bureau of Economic Analysis (BEA) uses U.S. Import and Export Price Indexes to adjust the net exports category of U.S. gross domestic product (GDP) for inflation. The indexes are used to deflate net exports. Net exports are measured as exports less imports. At any point in time, real net exports are the constant value estimate of trade, calculated by subtracting the value of imports from the value of exports, after each is deflated to constant dollars by dividing the aggregate import purchases and export sales by the Import and Export Price Indexes. Real net exports are expressed as

where

Trade balances published by the U.S. Census Bureau are adjusted for inflation using BLS Import and Export Price Indexes. In particular, the dollar value of trade, a component of the trade balances, is deflated using import and export prices. Doing so aligns the U.S. Census Bureau’s trade statistics with corresponding figures published by BEA.

Concepts and definitions of imports and exports

Price measurement in goods and services adheres to the concepts and definitions of U.S. balance of payments (BOP), also known as the U.S. international transactions accounts.^⁠1 For measurement purposes, the BOP concepts that are relevant to the U.S. Import and Export Price Indexes are U.S. resident and economic territory.

U.S. residents. This group includes individuals, governments, business enterprises, trusts, associations, nonprofit institutions, and similar organizations whose economic interests are centered in the United States and who reside or expect to reside in the United States for 1 year or more. U.S. residents do not need to be U.S. citizens or own property in the United States.

Economic Territory. For merchandise goods in the U.S. Import and Export Price Indexes, economic territory is composed of three categories: the U.S. Customs territory, which comprises the 50 states, the District of Columbia, and Puerto Rico; U.S. foreign trade zones (FTZs); and U.S. Customs bonded warehouses.

General imports. The total physical arrivals of merchandise from foreign countries, whether such merchandise enters consumption channels immediately or is entered into bonded warehouses or foreign trade zones.

Total exports. The total physical movement of merchandise out of the United States to foreign countries whether such merchandise is exported from within the U.S. Customs territory or from a bonded warehouse or a U.S. foreign trade zone (FTZ).

Air passenger fare imports. U.S. residents purchase these fares from foreign residents.

Air passenger fare exports. Foreign residents purchase these fares from U.S. residents.

Air freight imports. U.S. residents purchase these services from foreign residents.

Air freight exports. Foreign residents purchase these services from U.S. residents.

Inbound services. This index measures services coming from foreign destinations to the United States.

Outbound services. This index measures services going from the United States to foreign destinations.

The BOP definition of trade is based on the change-of-ownership principle. Trade can occur between related companies, foreign subsidiaries, or related or unrelated establishments or companies. In practice, the concept of ownership between U.S. residents and foreign residents is based on customs frontiers for trade in goods, and the flow of funds for trade in services. These frontiers are delineated by the concept of economic territory.

The U.S. Import and Export Price Indexes survey samples and collects prices on merchandise goods that are general imports and total exports. The scope of the services indexes is currently limited to transportation services and are comprised of the Import and Export Air Passenger Fares Indexes, the Import and Export Air Freight Price Indexes, and the Inbound and Outbound Air Freight Price Indexes.^⁠2 (Data Uses and Fact Sheets.)

Price and index concepts

The Bureau of Labor Statistics (BLS) strives to collect border transaction prices of imports and exports, which best reflect the prices buyers and sellers face. BLS may accept average prices, estimated prices, and list prices.

The transaction may occur between two unrelated parties or between companies that are commercially affiliated with each other. For affiliated companies, the price may be based on accounting considerations rather than market factors. Transaction prices are used regardless of whether or not they are market based.

Prices for items recorded in the U.S. Import and Export Price Indexes are based on accounting terms widely used for international commercial transactions or procurement processes. Examples of different price quotes that might be collected are listed here. The cost-basis price known as f.o.b. (free on board) foreign port is the price at the foreign port of exportation before insurance, freight, or duties are added. Another price basis is f.a.s. (free alongside ship), the price of the item at the U.S. port of embarkation. This price includes insurance charges plus the cost of transporting the good from the place of manufacture to the exit port. A third price basis option is c.i.f. (cost, insurance, freight). The IPP works with companies to specify the price quoted on the basis they are able to provide it consistently over time.^⁠3

For some product categories, alternative data sources are used in place of directly collected border transaction prices. These non-survey data sources may use other price definitions, such as spot prices and average prices. Spot prices are set in commodity markets and are used to transact trade around the world in raw materials and metals such as copper, silver, gold, and diamonds. Average monthly prices are used in instances where transaction data for a group of same-product transactions provide extensive coverage of trade, for which the product groupings approximate matched-item pricing across time. These alternative data sources are used because they are commonly agreed-upon price quotes for the traders in these products, they tend to reflect market price trends, and they are cost-effective.

Price indexes measure the average change in prices between periods; they do not measure price levels. The monthly movement in the price indexes measures the weighted averages of the price changes for each basket of traded items. These weighted changes of item prices in detailed groups are aggregated using algebraic formulas called index number formulas.

The price change of an item and resulting index change at the aggregate level capture market changes. The key price measurement concept used to capture the market effect is matched-item pricing which requires the business establishment to report the traded price of an identical item each month. Characteristics of the item, details of the transaction, and the price, including price basis, are recorded to validate the market price of an item. When a change to price-determining characteristics occurs for an item being priced in the survey, adjustments are made to remove the effects of these differences from the reported price to maintain the matched-item price change. The adjusted price is then considered the market price for the item and is used to calculate the price change between periods.

Coverage of goods and services

The U.S. Import and Export Price survey covers nearly all trade in merchandise goods, except for military goods, works of art, used items, charity donations, railroad equipment, items leased for less than a year, rebuilt and repaired items, and selected exports (custom-made capital equipment). The U.S. government’s administrative records of international trade as reported by business enterprises form the basis from which a sample of international trade transactions is selected. Items are identified from the companies selected and price information collected.

The U.S. Import and Export Price survey covers two services: air passenger fares and air freight prices. For air passenger travel, imports and exports are measured. For air freight transport, imports and exports as well as inbound and outbound prices are measured.

Some prices for goods and services are collected using alternative data sources. (See data sources.)

Units and periodicity of collection

For items whose price is reported by a respondent, the respondent provides the actual transaction price for an item traded as near as possible to the first day of a given month. Each price is reported by the establishment that conducted the trade. An establishment is a physical location of a business enterprise, and may be the entire business enterprise, or one worksite, such as a factory, warehouse, or headquarters of a large enterprise. A business enterprise may have more than one establishment participating in the U.S. Import and Export Price survey; the share of trade of an establishment in each detailed commodity group determines the establishment’s probability of selection for that commodity group.

For some prices from alternative data sources, the price transactions or quotes cover the 1-month period over the entire reference month of publication and then compare that with prices over the previous month. The method is used for items, such as petroleum, for which prices are volatile from one day to the next.

Adjustments are made when a price change results from changes in item characteristics. Adjustments are linked to specific items when the company providing the price can break out the price change based on the characteristic change. In cases where substantive change occurs to the item and it is no longer comparable even with adjustment, the item will be replaced if the difference cannot be measured accurately.

More information on how IPP selects establishments and items is available in the design section. Once selected, establishments are asked to provide prices on a monthly basis. In some cases where the item is actively traded monthly, but the price or characteristics for an item do not frequently change, the prices are provided less frequently than once a month.

Classification systems

Merchandise goods and services indexes are calculated under different classification systems. The goods included in the BLS U.S. Import and Export Price Indexes are mapped to three classification systems; two are commodity classifications and one is an industry classification.

The harmonized tariff schedule annotated (HTSA) for imports and schedule B for exports form the joint commodity classification system based on tariff regulations.^⁠4 All U.S. import and export trade are recorded using this classification system. This commodity classification is based on the harmonized system, which is a global classification system that provides an international naming convention to classify traded goods.

The HTSA/schedule B 10-digit level classifications are mapped to the two other classification systems used to calculate the U.S. Import and Export Price Indexes. These are the BEA end-use system, a product classification based on the principal use, which is used to calculate GDP, and the North American Industry Classification System (NAICS), an industry-based classification system.^⁠5 HTSA/schedule B product groups are matched to the detailed NAICS industry that produces similar domestic products. The NAICS indexes provide complementary indexes with many other official industry statistics. The historic trend of the U.S. Import and Export Price Indexes under the same classification category will differ given the different mix and weight of items that are in the import and export samples.

The air passenger and freight services measures use two trade-in-service classifications, the first being the balance of payments concepts, and the second being an international service classification that is also based on mode of supply. Both classifications measure the price trends for payments and receipts between U.S. residents and foreign residents for international services transactions.

Geographic coverage

The U.S. Import and Export Price Indexes are representative of trade in the 50 U.S. states and U.S. territories. Detailed HTSA product classification is the basis from which establishments with a share of trade in that product area are selected. Representative items from selected establishments and product areas are included in the sample for the U.S. Import and Export Price survey. Historically, the majority of U.S. trade has been carried out by a fairly concentrated number of business enterprises. All commodity categories (for goods) are represented in the sample which assures that the indexes are nationally representative, even though trade transactions that are selected for each commodity category and each physical establishment that received or sold the traded item may be concentrated in a geographical area. Goods indexes represent imports and exports for the United States and Puerto Rico. Import and export services indexes are based on cash flows and not geographic territory. Inbound and outbound air freight price indexes represent arrivals to and departures from the geographic area of the United States, Puerto Rico, and other U.S. territories and possessions.

The geographic location of an item’s foreign origin or destination is recorded for each item in the survey. The origin of foreign shipment to the United States and the destination of U.S. shipment to foreign locations are each evaluated as price-determining characteristics. Indexes that track price changes of product groups by locality of origin (imports) and/or of destination (exports) cover the following regions and countries:^⁠6

Both Imports and Exports

• The “Industrialized Countries” category comprises Western Europe, Canada, Japan, Australia, New Zealand, and South Africa
• The “Latin America” category comprises Mexico, Central America, South America, and the Caribbean
• The “Pacific Rim” category comprises China, Japan, Australia, Brunei, Indonesia, Macao, Malaysia, New Zealand, Papua New Guinea, Philippines, and Asian Newly Industrialized Countries
• The individual countries of Canada, China, Germany, Japan, and Mexico for both imports and exports, along with the United Kingdom, and France^{⁠ 7}

Imports only

• The “Asian Newly Industrialized Countries” category comprises Hong Kong, Singapore, South Korea, and Taiwan
• The “Association of Southeast Asian Nations” category comprises Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam
• The “Asia Near East” category comprises Bahrain, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, and Yemen
• Taiwan

Scope and exclusions

The U.S. Import and Export Price Indexes ideally should include all goods and services. As described previously, air freight price indexes and air passenger fares indexes are calculated. These are published separately from the merchandise goods import and export price indexes. Other import and export service categories are currently not covered due to a lack of funding.^⁠8

The U.S. Import and Export Price survey collects but does not publish actual prices of individual items or average prices of detailed product categories. This practice maintains confidentiality of business data and statistical standards. For this reason, the indexes cannot be used to measure differences in price levels among different products and services or among different localities of origin. For example, a higher index number for locality A (or product X) does not necessarily mean that prices are higher than for locality B (or product Y) with a lower index number. That only means prices have risen faster for locality A (or product X) since the reference period.

Because the U.S. Import and Export Price Indexes are primarily used as deflators, especially by BEA in calculation of real GDP, care must be exercised when using these data for other purposes. For example, import prices exclude charges for duties because BEA excludes duty when aggregating the net exports component of GDP and the denominator (prices) needs to match the numerator (GDP) when calculating the real value of net exports. Import prices would normally include duties if the objective were to provide a measure of domestic inflation of imported goods.^⁠9 If a 10-percent duty were placed on an imported item and the foreign company absorbed half of the tariff, passing the remainder on to the U.S. buyer, the duty-exclusive indexes produced by BLS would show approximately a 5-percent price decline. By contrast, an index including the duty as part of the price would show an increase of 5 percent.

The U.S. Import and Export Price Indexes are not seasonally adjusted. For those commodities subject to seasonal patterns of trade (air passenger fares) or for which world prices are affected by differences in seasons around the world (grains or vegetables), analysis of data over longer time spans or with rolling 12-month percent changes are the best measure excluding seasonality.

When items are priced in foreign currencies, exchange rates must be used to convert from a foreign currency price to a dollar price. A small share of imports and exports currently surveyed are priced in foreign currencies. The average daily exchange rate from the month prior to the reference month is used to convert prices into dollar terms before calculating indexes. More information on the impact of exchange rates is available in the presentation section.

Key variables of interest

The key variables of interest are the U.S. Import and Export Price Indexes for merchandise goods, including those published by locality of origin and locality of destination respectively, and for air passenger and air freight services, as well as the corresponding percent price changes and relative-importance values. Index measures are published only when value of trade, number of respondents, and number of price quotes maintain the quality of the index and protect the confidentiality of respondent information.

The U.S. Import and Export Price Indexes for merchandise goods are each calculated separately for two commodity classification systems and one industry classification system. Price indexes for goods are published to the four-digit level of product detail under the HTSA/schedule B classification system, and to the five-digit level of product detail under the BEA end-use system. Price indexes for goods industries are published to the six-digit level of industry detail under NAICS.^⁠10 There is one all-goods import price index measure, calculated as the aggregate of detailed BEA end-use system import price indexes.^⁠11 There is an analogous all-goods export price index measure.

The U.S. Import and Export Price Indexes for air passenger fares and air freight prices are published on a balance of payments classification, and the inbound and outbound price indexes for air freight prices use the general agreement on trade in services (GATS) international services classification.^⁠12 The service prices that compose each index are collected by country and published by country or region and for world trade.

Locality price indexes are country- and regional-NAICS import and export price indexes when sufficient data observations are available to support the greater level of detail. Industry coverage is from the two- to four-digit level of detail for imports, manufacturing, nonmanufacturing, and all goods for exports, when publishable, for different countries and regions. The goods prices that compose each industry index are collected by country and published by country or region. The aggregation by origin for each NAICS industry is the worldwide import price index of that NAICS industry, while the aggregation by destination for each NAICS industry is the worldwide export price index of that NAICS industry.

The relative importance of each published price index is provided in the monthly news release. This analytic measure provides details on the importance of a product group in trade and the degree of price movement that occurred in the product group. The relative importance is the percentage of an index’s price-updated value share of overall imports or exports at a specific point in time. Relative-importance values are affected by the trade weights at the point at which indexes are reweighted and by index changes relative to other indexes since the reweight point. If an index is rising in value relative to other indexes over time, the relative importance will increase as well. For example, if an import index value for a specific product area is 120.5, while the index value for overall imports is 102.3, the relative importance for that specific product has increased in time compared to the reweight period.

Price indexes and percent changes are published monthly. Prices are measured in U.S. dollars and price indexes are dollar-based indexes.

U.S. Import and Export Price Indexes process flow

In order to produce the U.S. Import and Export Price Indexes, the survey follows a process of selecting items to publish price indexes derived from those items. As shown in exhibit 1, the process includes sampling establishments, contacting establishments to enlist company participation in the survey, and setting up the establishments to regularly submit price information. Monthly price information for each item in the survey is collected. Survey staff review and validate the information and then calculate and publish indexes. (See illustration in exhibit 1.)

Exhibit 1.