Industry

Requirements tables are prepared for analytical uses of the benchmark I-O accounts, and are derived from the make and use table.  There are two types of tables, direct requirements and total requirements, which are produced in coefficient form.  Direct requirements coefficients show the amount of inputs purchased directly to produce one dollar of output.  Total requirements coefficients show the sum of direct and indirect purchases required to produce a dollar of output.  Indirect purchases necessary to produce an automobile, for example, would include the aluminum used

In the 1997, as well as the prior year Benchmark tables, government purchases are shown as part of final demand, as either government consumption expenditure or as government investment.  Input coefficients do not represent final demand, so there are no input coefficients for government.  If you need the data on purchases of government, use the final uses categories of the interactive I-O table when choosing industries.  It is important to note that government purchases are shown as intermediate inputs in the 2003 NIPA revision and the successive updated Annual I-O tables.

You can find a glossary and details about other I-O terms in “Concepts and Methods of the U.S. Input-Output Accounts.”

A good place to begin is the article in the December 2002 Survey of Current Business (SCB) article entitled “Benchmark Input-Output Accounts of the United States, 1997” which is available online at http://www.bea.gov/scb/pdf/2002/12December/1202I-OAccounts2.pdf.  This article also includes information about classification, valuation, and the treatment of secondary products in the Benchmark I-O tables.

Negative numbers mean different things depending on where you see them.  For example, in the government purchases column of the use table, a negative represents a government sale.  In the change in business inventory column, a negative represents a decrease in inventory.

The initial change in demand for the output of an industry directly affects the input of certain commodities and industries (direct requirements); this, in turn, generates an additional change to inputs for other industries and commodities (indirect requirements).

The December 2002 Survey of Current Business (SCB) article on the 1997 I-O accounts, “Benchmark Input-Output Accounts of the United States, 1997,” explains all the definitions and conventions used in the creation of the accounts.  The article is available online at http://www.bea.gov/scb/pdf/2002/12December/1202I-OAccounts2.pdf.  Subsequent changes in classification and definition can be found in the October 2007 SCB article “U.S.

General introductory information for the I-O tables is found in “Concepts and Methods of the U.S. Input-Output Accounts” and “Measuring the Nation’s Economy: an Industry Perspective, A Primer on BEA’s Industry Accounts.” Additionally, a collection of Survey of Current Business (SCB) articles is featured on the Industry product page under “Selected Documentation.”

The Census Bureau provides a concordance between the SIC and NAICS industry classifications on their web site. For both the 1992 and 1997 I-O tables, BEA provides a concordance between the codes used in the I-O tables and the Census industry (SIC or NAICS) classification.

Industry classifications using the NAICS classification system are described in the October 2007 Survey of Current Business (SCB) article “U.S. Benchmark Input-Output Accounts, 2002,” at http://www.bea.gov/scb/pdf/2007/10%20October/1007_benchmark_io.pdf . For a more detailed account of all the industries reported in each NAICS category, see the Census Bureau Web site at http://www.census.gov/econ/census02/