Redesigning the Consumer Price Index (CPI) Press Release Tables
The format of the tables contained in the CPI News Release will change
beginning with the CPI News Release for March, 2012, which will be issued
on Friday, April 13, 2012. News Release tables are currently available as
part of the News Release pdf and html files, and independently in html
format. The new tables will also be available in Excel format. In
addition, the BLS will begin issuing monthly companion Excel files, which
will contain additional index level and CPI-W information.
These tables were made available for public comment during October
2011. In response to the public comments, the BLS will issue Excel files
each month, as companions to the News Release. There will be CPI-U and
CPI-W files, and in addition to the data contained in the News Release
tables, the Excel files will contain index values. Samples of the
companion Excel files will be available with the February CPI News Release
in March 2012. Samples of the new
CPI press release tables are available.
In August 2009, the Bureau of Labor Statistics (BLS) restructured the
text of the CPI press release to focus on the price movements of three
broad expenditure categories, namely Food, Energy, and All items less food
and energy. Table A within the CPI press release text was also updated in
August 2009 to reflect this new structure. Before August 2009, the text of
the CPI press release had focused on eight CPI ‘major groups’ (Food and
beverages; Housing; Apparel; Transportation; Medical care; Recreation;
Education and communication; and Other goods and services).
While the text of the CPI press release was restructured in 2009, seven
additional CPI press release tables continued to be published using the
eight major groups. BLS has redesigned these press release tables, to
reflect the focus on Food, Energy, and All items less food and energy.
Within these three broad categories, CPI item series will be further
divided into commodities and services. The CPI News Release will contain
these updated tables beginning with the March 2012 News Release, to be
issued on Friday, April 13, 2012.
Beyond the redesign in the structure of the CPI press release tables,
several other improvements to these tables have been made.
The new Table 1 gives a summary of the index series which typically
contribute to changes in the Consumer Price Index for All Urban Consumers
(CPI-U).
The new Table 2 will show the full publication stub using the new
structure for the CPI-U, including 11 new items series that were created
to augment the redesign in the publication structure. Table 3 will show
aggregate item series (e.g., Transportation) that do not fall under the
Food, Energy, and All items less food and energy structure.
Table 4 will show the All items indexes at the local, regional, and
city-size class levels.
Table 5 will show the Chained Consumer Price Index for All Urban
Consumers (C-CPI-U), and presents a history of annual percentage changes
in the C-CPI-U compared to the CPI-U.
Table 6 will focus on 1-month seasonally adjusted changes in the CPI-U,
while table 7 will focus on 12-month not seasonally adjusted changes.
Tables 6 and 7 will present three additional pieces of data to help users
better interpret index changes. First, these tables will show the ‘effect’
each item has on the price change for All items. For example, if the
effect of food is 0.4, and the index for All items increased 1.2 percent,
it can be said that increases in food prices accounted for 0.4 / 1.2, or
33.3 percent, of the increase in overall prices for that period. Said
another way, had food prices been unchanged, the All items index only
would have increased 0.8 percent (or 1.2 percent for All items, minus the
0.4 effect for Food). Effects can be negative as well. For example, if the
effect of food was a negative 0.1, and the All items index rose 0.5
percent, the All items index actually would have been 0.1 percent higher
(or 0.6 percent) had food prices been unchanged.
Second, standard errors for percent changes will be shown on tables 6
and 7. Confidence intervals for statistics can be created using standard
errors; e.g., roughly 95% confidence intervals can be constructed using
two standard errors. For example, if an item increased 3.7 percent, and
its standard error was 0.6 percent, the 95% confidence interval for that
price change can be said to be 3.7 percent plus or minus two standard
errors, or 3.7 percent plus or minus 1.2 percent.
Finally, each item series in tables 6 and 7 will show the last time
that item had a price change as large (or as small) as the percent change
published that period. For example, if bananas rose 3.7 percent, and that
was its largest increase since November 2007, that would be noted in the
new tables.
In addition, most of the existing tables show the ‘relative
importance’, or weight, of each item category as of the previous December.
The relative importance columns in the new tables will be improved in that
they will be updated monthly to reflect the change in relative prices over
time.
Finally, there will no longer be any press release tables that focus on
the Consumer Price Index for Urban Wage Earners and Clerical Workers
(CPI-W). That said, the CPI-W All items index level and percent changes
will still be noted in the text of the press release, and a companion
Excel file with CPI-W information will be available.
Sample files (using November 2011 data) are available:
Mock-up of CPI News Release Tables in PDF
Mock-up of CPI News Release Tables in XLS
Mock-up of CPI News Release Tables in HTML
Last Modified Date: January 19, 2012
