Introducing a new way to navigate by topics. Access the latest news, data, publications and more around topics of interest.
Our population statistics cover age, sex, race, Hispanic origin, migration, ancestry, language use, veterans, as well as population estimates and projections.
This section provides information on a range of educational topics, from educational attainment and school enrollment to school districts, costs and financing.
We measure the state of the nations workforce, including employment and unemployment levels, weeks and hours worked, occupations, and commuting.
Our statistics highlight trends in household and family composition, describe characteristics of the residents of housing units, and show how they are related.
Health statistics on insurance coverage, disability, fertility and other health issues are increasingly important in measuring the nation's overall well-being.
We measure the housing and construction industry, track homeownership rates, and produce statistics on the physical and financial characteristics of our homes.
The U.S. Census Bureau is the official source for U.S. export and import statistics and regulations governing the reporting of exports from the U.S.
The U.S. Census Bureau provides data for the Federal, state and local governments as well as voting, redistricting, apportionment and congressional affairs.
Search an alphabetical index of keywords and phrases to access Census Bureau statistics, publications, products, services, data, and data tools.
Geography provides the framework for Census Bureau survey design, sample selection, data collection, tabulation, and dissemination.
Geography is central to the work of the Bureau, providing the framework for survey design, sample selection, data collection, tabulation, and dissemination.
Find resources on how to use geographic data and products with statistical data, educational blog postings, and presentations.
The Geographic Support System Initiative will integrate improved address coverage, spatial feature updates, and enhanced quality assessment and measurement.
Work with interactive mapping tools from across the Census Bureau.
Find geographic data and products such as Shapefiles, KMLs, TIGERweb, boundary files, geographic relationship files, and reference and thematic maps.
Metropolitan and micropolitan areas are geographic entities used by Federal statistical agencies in collecting, tabulating, and publishing Federal statistics.
Find information about specific partnership programs and learn more about our partnerships with other organizations.
Definitions of geographic terms, why geographic areas are defined, and how the Census Bureau defines geographic areas.
We conduct research on geographic topics such as how to define geographic areas and how geography changes over time.
Visit our library of Census Bureau multimedia files. Collection formats include audio, video, mobile apps, images, and publications.
Collection of audio features and sound bites.
The Census Bureau packages data and information into easy-to-understand visuals.
Browse Census Bureau images.
Read briefs and reports from Census Bureau experts.
Watch Census Bureau vignettes, testimonials, and video files.
Read research analyses from Census Bureau experts.
Access data through products and tools including data visualizations, mobile apps, interactive web apps and other software.
Developer portal to access services and documentation for the Census Bureau's APIs.
Explore Census Bureau data on your mobile device with interactive tools.
Find a multitude of DVDs, CDs and publications in print by topic.
These external sites provide more data.
Download extraction tools to help you get the in-depth data you need.
Learn more about our data from this collection of e-tutorials, presentations, webinars and other training materials. Sign up for training sessions.
Explore Census data with interactive visualizations covering a broad range of topics.
Learn how we serve the public as the most reliable source of data about the nation's people and economy.
How we provide the best mix of timeliness, relevancy, quality, and cost for the data we collect.
Our researchers explore innovative ways to conduct surveys, increase respondent participation, reduce costs, and improve accuracy.
Our surveys provide periodic and comprehensive statistics about the nation, critical for government programs, policies, and decisionmaking.
Learn about other opportunities to collaborate with us.
Explore the rich historical background of an organization with roots almost as old as the nation.
Explore prospective positions available at the Census Bureau.
Explore Census programs targeted for particular needs.
Discover the latest in Census Bureau data releases, reports, and events.
The Census Bureau's Director writes on how we measure America's people, places and economy.
Find interesting and quirky statistics regarding national celebrations and major events.
Listen to audio files on fun facts, historical figures, and celebrations of the month.
Find media toolkits, advisories, and all the latest Census news.
See what's coming up in releases and reports.
Click here for a PDF version of this documentPrepared by Foreign Trade Division
The U.S. Census Bureau (Census) introduced a new constant dollar series
(2000 = 100) in the April 2003 release of the FT900, "U.S. International
Trade in Goods and Services". The fixed-weighted series, published
since 1990, was discontinued at that time. This paper explains the chained
Fisher methodology, its benefits, and where additional information on
the chained Fisher methodology can be found.
Census adopted the new chained Fisher methodology to improve the quality of the data series and restore the consistency of the Census Bureau's constant dollar (real) data with the Bureau of Economic Analysis's (BEA) National Income and Product Accounts (NIPA), as required by the Omnibus Trade and Competitiveness Act of 1988. The chained Fisher methodology improved the quality of the series by eliminating the substitution bias, that is, the tendency of fixed-weighted series to misstate growth as one moves further from the base year . This tendency reflects the fact that the commodities, for which output grows rapidly, tend to be those for which prices increase less than average or decline. Elimination of the substitution bias was the driving force behind BEA's adoption of the chained Fisher methodology.1
The Fisher index consists of two components, the Paasche and Laspeyres indexes. The Paasche index uses weights based upon the month for which the index is calculated. The Laspeyres index is base-weighted, so the quantity of the previous month provides the weights. The primary weakness of the Paasche and Laspeyres indexes is the substitution bias. The chained Fisher methodology brings the two indexes together in the form of a geometric mean and chains the data back to the base period, thereby minimizing the substitution bias.
The new real dollar series is available in Exhibits 10 and 11 of the monthly FT900. Historical data from 1994-2000 and the 2002 Final Revisions (Exhibits 9, 9a, and 10) are available on the Foreign Trade Website (http://www.census.gov/foreign-trade/www/). Census plans to develop and maintain a minimum of 10 years of chain-weighted dollar data.
The chained Fisher methodology uses fixed-weighted deflators to estimate the price (p) of each good and fixed-weighted real dollars (seasonally adjusted current dollar value ÷ deflator) to estimate the quantity (q). The first step is to calculate Paasche, Laspeyres, and Fisher indexes for all import and export end-use categories (for example: import and export feeds, foods, and beverages; import and export industrial supplies and materials; and import and export capital goods) for each processing month and year based upon the prior processing month:
In the equations, t = the current processing month and year,
t-1 = the prior processing month,
C = the import or export aggregated category,
pt = deflator for 5-digit commodity e in time period t, and
qt = seasonally adjusted current dollar value for 5-digit commodity e in time period t divided by deflator for 5-digit commodity e in time period t.
These month-to-month Fisher indexes are then chained together from the first time period (t1) to create a chain type index with base period t1:
The Chain Type Quantity Index for base period t1 is set equal to 1. The Chain Type Quantity Index is then adjusted to the desired base year (currently 2000) by dividing by the average Chain Type Quantity Index for the base year (BYR):
The Fisher Chained Quantity Index and base year Average Current Dollar Value are used in calculating the real value in chain-weighted dollars:
Most of the deflators used in the calculation of the new chain-weighted series are from the U.S. Import Price Indexes (MPI) and U.S. Export Price Indexes (XPI), published by the Bureau of Labor Statistics (BLS). Census generally uses the most detailed Import and Export Price Index categories (usually a 3- or 5-digit end-use code) available with the following exceptions:
Census uses the Producer Price Indexes, produced by BLS, to deflate
imports and exports of non-monetary gold; railway transportation equipment;
civilian aircraft; spacecraft, excluding military; vessels, excluding
scrap; commercial vessels, other; marine engines, parts; exports of semi-conductors;
and precious metals, other
Census uses a combination of import, export, and producer price indexes to deflate imports and exports of computers and computer accessories
Census also uses import trade data to calculate unit value indexes in order to deflate imports of petroleum and electricity.
Census uses an overall implicit Fisher index, excluding volatile commodities, to deflate Other Goods'. This category consists of import and export minimum value shipments; import military aircraft and parts thereof; other military equipment; U.S. goods returned and re-imports; export military-type goods; miscellaneous domestic exports and special transactions; and undocumented exports to Canada. Petroleum, computers, computer accessories, and semi-conductors are excluded from the calculation of the import implicit deflator, while computers, computer accessories, and semi-conductors are excluded from the export calculation.
The fixed-weighted and chain-weighted methodologies use the same data, but in different ways. The advantage of the fixed-weighted constant dollar series is its simplicity. The fixed-weighted value is a simple division of the seasonally adjusted current dollar value for each end-use category by the appropriate deflator. The value for each published category is obtained by summing the deflated values for each 5-digit end-use code in that category. This methodology has several disadvantages. The selection of the base year can significantly affect the month-to-month changes, so that estimates of growth can change significantly when a fixed-weighted series is rebased. This methodology also is affected by substitution bias. The fixed-weighted method does not allow for goods to be substituted for one another when relative prices change; it assumes that changes in price do not affect the amount of goods purchased.
One obvious difference between the fixed-weighted and chain-weighted methodologies is that the chain-weighted dollars are not additive. For example, the sum of the six principal end-use categories for imports in Exhibit 10 does not sum to total imports. The residual difference' between the sum of the categories and the total will vary from month-to-month. These residuals are displayed in each exhibit. As the chain-weighted dollars move further from the base year, the residuals tend to become larger.
In contrast to the fixed-weighted, the chained Fisher methodology minimizes substitution bias. This methodology compares each month to the previous month, weighting those changes by the importance of each good in both periods, and chaining back to the base period. Changes in the goods traded are incorporated very quickly into the deflators, thereby minimizing substitution bias, and rebasing does not affect month-to-month changes.
It is important to note that the real dollar values produced by Census and BEA will still differ. The two agencies present the data in different forms. The data published by BEA each quarter is presented on an annualized basis, using quarterly chaining. Census uses monthly chaining and publishes monthly real dollars. However, the largest differences result from underlying differences between the Census and NIPA current dollar data.
The NIPA figures are presented on a balance of payments basis, which includes adjustments to the merchandise trade data for valuation and coverage differences. The NIPA exclude the repairs of goods, developed motion picture film, electricity, and military type goods; all of which are covered under the services accounts. In addition, imports into and exports from the U.S. Virgin Islands and Puerto Rico are excluded from the NIPA as are exports of non-monetary gold. The BEA makes some additional adjustments for timing and other coverage differences.
1 - Landefeld, J. Steven and Robert P. Parker. "Preview of the Comprehensive Revision of the National Income and Products Accounts: BEA's New Featured Measures of Output and Prices". Survey of Current Business (July 1995): 1-38.
For further information on Census procedures for adjusting merchandise trade data for price change contact the Special Projects Branch, Foreign Trade Division, U.S. Department of Commerce, U.S. Census Bureau, Washington, D.C. 20233, phone (301)763-3251, fax (301)457-2104.
For information about the NIPA and the deflators used by BEA, contact the National Income and Wealth Division, U.S. Department of Commerce, Bureau of Economic Analysis, 1441 L Street NW, Washington, D.C. 20220 or refer to the following articles on their website, http://www.bea.gov:
Landefeld, J. Steven and Robert P. Parker. "Preview of the Comprehensive Revision of the National Income and Product Accounts: BEA's New Featured Measures of Output and Prices". Survey of Current Business (July 1995): 31-38.
Landefeld, J. Steven and Robert P. Parker. "BEA's Chain Indexes, Time Series, and Measures of Long Term Economic Growth". Survey of Current Business (May 1997): 58-68.
Seskin, Eugene P. and Robert P. Parker. "A Guide to the NIPA's". Survey of Current Business (March 1998): 26-68.
For information about the BLS International Price Indexes, contact the
International Price Division, Bureau of Labor Statistics, U.S. Department
of Labor, Washington, D.C. 20212, (202)691-7101.
Deficit: $44.4 Billion
Exports: $195.5 Billion
Imports: $239.8 Billion
Next release: August 6, 2014
Complete Release Schedule
Collection of videos to enhance export training.
Aug 20-21, 2014