Gross-Domestic-Product-by-Industry Accounts
Annual Industry Accounts Methodology
The annual input-output (I-O) accounts and the
GDP-by-Industry accounts are created using an integrated methodology that makes
the annual estimates of gross output, intermediate inputs, and value added by
industry more timely and consistent than previously possible.[1] Industry estimates are published for 65
detailed industries, as defined by the 1997 North American Industry
Classification System (NAICS). Commodity
estimates are published at the same level of detail plus four unique
commodities.[2] Extensive estimates of final uses and value
added are also included in the annual publication. Compared to previous methodologies, the
integrated methodology is applied at a finer level of industry and commodity
detail to enhance the accuracy of aggregate level estimates.
The integrated annual I-O accounts and GDP-by-industry
accounts are prepared in five steps.
Step one. Industry estimates of current-dollar value
added are extrapolated forward by the percentage changes in the annual
estimates of gross domestic income (GDI) from the NIPAs. The GDI-by-industry estimates consist of
compensation of employees, taxes on production and imports less subsidies, and
gross operating surplus. Additionally, BEA
uses data on employment to convert the corporate data on profits before tax,
net interest, and capital consumption allowances from an enterprise basis to an
establishment basis. Finally, the
statistical discrepancy, the difference between GDI and GDP from the NIPAs, is
distributed among the industries. In
general, annual revisions to the industry estimates of value added largely
reflect revisions to the components of GDI and to the statistical discrepancy
from the annual NIPA revision.
Step two.
Industry estimates of gross domestic output. The extrapolators for these estimates are
prepared using a wide array of source data, which include surveys from the
Bureau of the Census and the Bureau of Labor Statistics, 2002 Economic Census
data for manufacturing, and other data.[3] Annual revisions to industry estimates of
gross output are due to revisions in these source data.
Step three.
The initial commodity composition of intermediate inputs is calculated
for each industry by a process that uses the previous year’s direct requirements
coefficients. First, the industry’s
gross output for a given year is revalued in the commodity prices of the
previous year. Next, the revalued gross
output is multiplied by the industry’s direct requirements coefficients from
the previous year.[4] Finally, the resulting commodity estimates of
intermediate inputs for the industry are revalued in the commodity prices of
the current year.
Step four.
The domestic supply of each commodity
and the commodity composition of each GDP expenditure component are
estimated. The initial commodity
compositions for these expenditure components are estimated using
commodity-flow relationships from the revised 1997 benchmark I-O accounts. The annual I-O use tables are then balanced
using a bi-proportional adjustment procedure to ensure that intermediate and
final use of commodities is consistent with domestic supply, that intermediate
use is consistent with gross output and value added, and that final use is
consistent with the final expenditure components from the NIPAs. The measures of gross output, intermediate
inputs, and value added are then incorporated into the GDP-by-industry
accounts.
Step five. Price and quantity indexes for the GDP-by
industry accounts are prepared in three steps.
First, indexes are derived for gross output by separately deflating each
commodity produced by an industry that is included as part of its gross
output. Next, indexes for intermediate inputs
are derived by deflating all commodities that are consumed by an industry as
intermediate inputs in the annual I-O use tables.[5] Finally, indexes for valued added by industry
are calculated using the double-deflation method in which real value added is
computed as the difference between real gross output and real intermediate
inputs.[6]
[1] For more information pertaining to the integrated
annual industry accounts, see Brian C. Moyer, Mark A. Planting, Mahnaz
Fahim-Nader, and Sherlene K.S. Lum, “Preview of the Comprehensive Revision of
the Annual Industry Accounts,” Survey of Current Business 84 (March 2004): 38-51.
http://www.bea.gov/bea/pub/0304cont.htm
[2] These special commodities consist of noncomparable
imports; scrap, used and secondhand goods; rest of the world adjustment to final
uses; and inventory valuation adjustment.
[3] The estimates of the commodity composition of
extrapolated industry gross output are largely consistent with the 1997
benchmark I-O relationships for nonmanufacturing industries and with current
survey data for manufacturing industries.
[4] Direct requirements coefficients specify the
amount of each commodity required by the industry to produce a dollar of
output.
[5] Source data used to prepare the commodity price
indexes for deflation can be found in Moyer et al. 48-49.
[6] Separate estimates of gross output and
intermediate inputs are combined in a Fisher index-number formula in order to
generate the indexes for value added by industry. This method is preferred because it requires
the fewest assumptions about the relationships among gross output by industry
and intermediate inputs by industry.
Gross-Domestic-Product-by-Industry Accounts Help
Gross-Domestic-Product-by-Industry Press Release
Guide to the Interactive GDP by Industry Accounts Tables
Annual Industry Accounts Methodology Summary
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