Methodology notes for Amber
Waves Indicators
Measuring nonmetro-metro difference in poverty
rates
Robert
Gibbs
The Census Bureau has not released official metro/nonmetro
poverty estimates for 2004 due to sample redesign
in the Current Population Survey (CPS). The
current metro/nonmetro classification, based on
the 2000 Census, was phased in over a period of
several months, including the period in which households
were asked about their 2004 incomes. As
a result, the metro designation assigned to CPS
households during this period is a mix of the old
and new classifications, preventing a consistent
measure of nonmetro poverty rates.
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Measuring agriculture's
contribution to Gross Domestic Product
Paul
Sundell
Each issue of Amber Waves
includes a set of indicators relevant to the farming,
rural, natural resource, and food sectors of the
U.S. economy. Among those indicators are two measures
designed to capture agriculture’s contribution
to Gross Domestic Product (GDP). Recently, a new
methodology for calculating those measures was introduced
in Amber Waves. Under the new methodology, the scope
of the agriculture measure is essentially the same.
For the measure that captures agriculture and related
industries, however, the scope has narrowed with
the new methodology.
Until September 2005, the measures
published in Amber Waves—food and
fiber sector share and farm sector share—came
from ERS’s food and fiber system (FFS) data
series, which was discontinued in 2002. The current
measures, introduced in September 2005, are derived
using value-added industry estimates from the Bureau
of Economic Analysis (BEA) National Income and Product
Accounts. The value-added or net output of an industry
is its gross output less the value of inputs obtained
from outside the industry. The new measure defines
the share of GDP attributed to agriculture and related
industries more narrowly than the previous measure
(which was called the food and fiber sector share).
Specifically, agricultural and
related industry sector output is defined as the
sum of the valued-added outputs of the following
industries: farms, forestry, fishing, hunting, processed
food, beverage, and tobacco products, textile and
leather apparel, restaurants and drinking establishments.
Some value-added payments reflect agricultural activities
generated by nonagricultural demands. These industries
were chosen to be included in the measure because
of the key role of agricultural inputs in these
industries and the availability of industry value-added
data. BEA computes industry value-added estimates
by using the actual gross output levels of each
sector and the input output relationships within
and across sectors.
In 2004, agriculture and related
industries had a 4.8 percent value-added share of
nominal GDP, consisting of a 1.0-percent share for
farms; a 1.4-percent share for processed food, beverage,
and tobacco products; a 1.8-percent share for food
service and drinking establishments; a 0.4-percent
share of textile and leather apparel; and a 0.3-percent
share for forestry, fishing, and hunting.
For
a detailed discussion of FFS methodology see
. . . |
Measuring the Economywide
Effect of the Farm Sector: Two Methods,
by William Edmondson, Mindy Petrulis, and
Agapi Somwaru, TB-1843, USDA, Economic Research
Service, July 1995.
The
Food and Fiber System: Contributing to the
U.S. and World Economies, Kathryn
L. Lipton, William Edmondson, and Alden Manchester,
AIB-742, USDA, Economic Research Service,
July 1998.
|
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Measuring the Importance of Trade
to U.S. Agriculture
Alberto Jerardo
Starting with the November 2003 edition of Amber
Waves, ERS has published a volume-based
measure of exports relative to production, which
provides an aggregate indicator of the importance
of trade to agriculture. The export share
of the volume of U.S. agricultural production
is estimated from the sum of export volumes of
commodities and processed products divided by
their corresponding total volume of farm production. To
be consistent with production volumes and to
represent export importance at the farm level,
processed export volumes are converted to farm
weight or fresh-weight equivalent using industry
conversion factors.
U.S. agricultural commodities and their products
are generally classified as either produced from
livestock or from crops. Livestock products
include red meats, poultry meats, dairy products,
eggs, animal fats and oils, and live farm animals. Except
for live animals, exported livestock products undergo
some form of processing. The major groups
for crops include food grains, feed grains, oilseeds,
fruits and nuts, vegetables, sugar, cotton, and
tobacco.
As a rule, all agricultural commodities and products
whose export and corresponding production volumes
are available or convertible to weight measures
were included in calculating the aggregate export
share of U.S. agricultural production. Exports
of these categories comprised 78 percent of the
total value of U.S. agricultural exports in 2005.
As of February 2007, three major changes
were made in the estimate of export volume shares
of processed agricultural products:
- For oilseeds, oilmeal, and vegetable oils,
only total oilseed production volume is used
as the denominator. Previously, production
volumes of oilmeal and vegetable oils were added
to oilseed volume, which overestimated the denominator. In
addition, oilseed-equivalent weights of oilmeal
and vegetable oil exports are now used in place
of their product weights.
- Exports of grain products such as pasta are
now included, using total U.S. grain production
as the denominator. These products were
previously excluded.
- Processed fruit and vegetable exports are now
converted to farm weight. Formerly, their
product weights were used.
These changes increased the volume of U.S. agricultural
exports relative to their production volume, thus
raising the collective export share of production.
For
more information. . . |
Measuring
the Importance of Exports to U.S. Agriculture,
by Nora Brooks, in Amber Waves, Volume
4, Issue 5, USDA, Economic Research Service,
February 2007.
Estimating
Export Shares of U.S. Agricultural Production, by Alberto
Jerardo, in Amber
Waves, Volume 1, Issue 5, USDA, Economic
Research Service, November 2003. |
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