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Issue 5, September/October 2003
Federal Reserve Bank of Dallas
Beyond the Border
(Mis)reporting Mexico’s Gross Domestic Product
The health of Mexico’s economy
is important to business people and analysts in the United
States. This is especially true in Texas, which shares a 1,254-mile
border with Mexico and whose economy is closely related to
that of its southern neighbor. For example, approximately
43 percent of Texas’ exports flow to Mexico. Perhaps
the most closely watched indicator of the Mexican economy
is quarterly Gross Domestic Product (GDP), published by Mexico’s
Instituto Nacional de Estadística, Geografía
e Informática (INEGI). This article cautions followers
of Mexico GDP that the media have misinterpreted the recent
GDP statistics, resulting in reports that exaggerate the weakness
in Mexico’s economy.
INEGI released second-quarter 2003 GDP
statistics on Aug. 15. News media characterized the results
as continued weakness in the Mexican economy. According to
Reuters, “Mexico’s economy slowed in the second
quarter to post anemic year-on-year growth of 0.2 percent
in the second quarter....” The headline of a Wall
Street Journal story read, “Mexico’s GDP
Barely Grew in the Second Quarter.” Market News International
reported, “Mexico’s gross domestic product grew
a paltry 0.2% year-over-year in the second quarter, following
a 2.3% rise in the prior quarter....” Dow Jones said,
“Output of goods and services in Mexico grew modestly
in the second quarter....”
The United States and most other countries
routinely report GDP statistics that have been statistically
adjusted to remove the effects of seasonality, the presence
of which makes quarter-to-quarter comparisons difficult. For
example, there is always a decline in GDP from the fourth
quarter of one year to the first quarter of the next because
of a ramp-up in production for the Christmas season and a
decline in economic activity following Christmas. One would
need to know the normal magnitude of this decline to know
whether a particular fourth-quarter to first-quarter change
meant strength or weakness in the economy. Seasonal adjustment
removes this confounding effect from the data and makes comparisons
from quarter to quarter straightforward. Until recently, reliable
seasonally adjusted Mexico GDP data were not generally available.
Therefore, analysts and the media have tended to focus on
year-over-year comparisons—which should at least be
free of the clouding influence of seasonality—although
they don’t provide information on the most recent trends.
One factor that makes such year-over-year
comparisons of Mexico’s GDP highly unreliable is the
tendency for the Easter holiday to move around in the calendar.
Easter can fall as early as March 22 or as late as April 25.
In many Latin American countries, economic activity declines
during the week or so prior to Easter. La Semana Santa, or
Holy Week, runs from Palm Sunday to Easter Sunday and is a
period of reduced economic activity during which many Mexicans
take vacation. When Easter occurs in March or early April,
the lull in economic activity shows up in first-quarter figures.
When Easter occurs later in April, the lull manifests itself
in second-quarter data. Clearly, a year-over-year comparison
in which Easter does not occur in the same quarter in both
years will produce an unreliable estimate of true economic
growth.
In 2002, Easter fell on March 31, depressing
economic activity in the first quarter. In 2003, Easter occurred
on April 20, exclusively affecting second-quarter data. The
year-over-year GDP growth of 2.3 percent, measured as of the
first quarter of 2003 in the unadjusted data, is biased upward,
while the 0.2 percent year-over-year growth, measured as of
the second quarter of 2003, is biased downward. These are
the figures being widely cited in media reports.
Following
a joint effort with the Finance Ministry and the Bank of Mexico,
INEGI began publishing seasonally adjusted GDP data with its
release of first quarter 2003 data on May 15. The new statistical
series is calculated using the X12-Arima procedure, which
has appropriate tools for correcting the moving Easter problem.
In the adjusted data, the year-over-year GDP growth rates,
measured as of the first and second quarters of 2003, are
1 and 1.4 percent, respectively (Chart 1). Compare
these figures with the previously cited 2.3 percent and 0.2
percent from the unadjusted data. We see a less volatile and
accelerating growth pattern using the unbiased data.
The new seasonally adjusted GDP series
is better not only because it allows unbiased calculation
of year-over-year growth, but also because it allows meaningful
quarter-to-quarter comparisons. INEGI’s Aug. 15, 2003,
press release reports that seasonally adjusted GDP increased
by 1.21 percent from the first quarter of 2003 to the second
quarter, following a decline of 0.4 percent from the fourth
quarter of 2002 (Chart 2). Most of the media sources
we surveyed did not mention quarter-to-quarter growth at all.
Those that did seemed not to know what to make of it, reporting
it without comment and without noting the inconsistency of
the second-quarter figure with their characterization of poor
performance in the second quarter, based on the 0.2 percent
year-over-year figure. The 0.2 percent figure is wrong because
it includes the Easter bias. Furthermore, it is misleading
to treat the year-over-year growth measure as if it reflects
recent activity. The media reports cited earlier repeatedly
use the phrase, “in the second quarter.” It is
important to note that these reports refer to growth over
an entire year, not growth in the second quarter.
What
are the data really saying? First, GDP growth during the preceding
year, measured as of second quarter 2003, was 1.4 percent,
not 0.2 percent as has been widely reported. Second, GDP growth
between the first and second quarters of 2003 was 1.21 percent
(which is a robust 4.9 percent, annualized), up from the 0.4
percent decline in the previous quarter. It is beyond the
scope of this article to speculate about whether Mexico’s
economy is emerging from recession. Other economic indicators
suggest that is not the case. Suffice to say that media reports
have underreported Mexico’s GDP growth during the last
year and that growth has, in fact, accelerated recently.
The introduction of the new seasonally
adjusted GDP data has contributed greatly to our ability to
assess the performance of Mexico’s economy. In time,
analysts and the media will learn to put this information
to best use—both to calculate meaningful year-over-year
comparisons and to pay increased attention to quarter-to-quarter
changes.
—Franklin D. Berger
| About the Author
Berger is director of technical
support and data analysis in the Research Department
of the Federal Reserve Bank of Dallas.
About Southwest Economy
Southwest Economy
is published six times annually by the Federal
Reserve Bank of Dallas. The views expressed are
those of the authors and should not be attributed
to the Federal Reserve Bank of Dallas or the Federal
Reserve System.
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Southwest Economy
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