Have events related to the September 11th terrorist attacks
had any effect on Bureau of Labor Statistics data collection?
In the weeks following the terrorist attacks of September 11, disruptions
of postal service made necessary by the detection of contaminants in the
mails have had some limited impacts on Bureau of Labor Statistics data
The response rate for the October Producer Price Index was reduced
to approximately 80 percent of its normal level. A review was undertaken to
evaluate the impact of lower response rates on survey estimates. No unusual
effects were found.
Postal service disruptions did not affect the overall level of Current
Employment Statistics (CES) sample receipts for October. Approximately 80
percent of the CES sample data are collected through automated methods and
about 20 percent of the sample respondents report by mail. For the
mail-collected units, October receipts were at a normal level.
Similarly, despite the disruption in postal service, response rates for
the Import and Export Price Index surveys for October were not appreciably
different from normal levels.
The September 11 attacks themselves occurred during the reference week
(September 9-15) for the Current Population Survey (CPS) of households. Data
collection began as regularly scheduled on Sunday, September 16, and
continued into the week of September 23. Octobers data collection efforts
also were conducted on their regular schedules. The September and October
survey response rates, both nationwide and in the New York City area, were
normal. The Current Population Survey is based entirely on telephone
contacts and personal visits; it was not affected by special mail handling
The events of September 11 also occurred during the reference period for
the Employment Cost Index (ECI). A review of ECI survey responses undertaken
to evaluate the impact of the situation on the surveys cooperation rates
by industry and any impact of nonresponse on survey estimates found no
Last Modified Date: November 9, 2001