The impact of classification changes on time series continuity the case of u s monthly retail sales
Sponsored Links
This presentation is the property of its rightful owner.
1 / 13

Presented to OECD Short-Term Economic Statistics Working Party By: Thomas E. Zabelsky PowerPoint PPT Presentation


  • 74 Views
  • Uploaded on
  • Presentation posted in: General

The Impact of Classification Changes on Time Series Continuity The Case of U.S. Monthly Retail Sales. Presented to OECD Short-Term Economic Statistics Working Party By: Thomas E. Zabelsky Chief, Manufacturing and Construction Division [email protected] June 26, 2006.

Download Presentation

Presented to OECD Short-Term Economic Statistics Working Party By: Thomas E. Zabelsky

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


The Impact of Classification Changes on Time Series ContinuityThe Case of U.S. Monthly Retail Sales

Presented to

OECD Short-Term Economic Statistics Working Party

By: Thomas E. Zabelsky

Chief, Manufacturing and Construction Division

[email protected]

June 26, 2006


Importance of Time Series

  • Historical description of occurrence or phenomena

  • Analyzing and interpreting economic conditions

  • Basis for forecasting


Time Series Continuity

  • Requires –

  • Continuous series of observations

  • Standard methods and definitions


Changing Industrial Classifications

  • The dilemma -

  • Keeps pace with evolving industrial and business activities, but

  • Interrupts continuity of time series data


North American Industry Classification System (NAICS)

  • Clean slate revision to earlier system

  • First NAICS-based data published from 1997 Economic Census


Impact of NAICS on Industry Classifications

  • 1,170 industries – 15% increase over SIC

  • Industries

  • -350 new

  • -390 revised

  • -422 substantially unchanged


Impact of NAICS on Retail Trade

  • Old SIC division split into two NAIC sectors

  • -retail trade

  • -accommodations and food services

  • Retail trade

  • -15 industries; 10 new

  • -eating and drinking places accounted for 10% in retail SIC

  • -retail-wholesale boundary issues


Impact of NAICS on Retail Trade Data

  • Source:1997 Economic Census


Sources of Change on NAICS-BasedRetail Data

  • Source:1997 Economic Census


Restructuring Retail Time Series Data

  • Restated 1992 Economic Census sales on a NAICS basis

  • -assigned NAICS code to each employer establishment with an SIC that directly converted to NAICS (74%)

  • -Matched employer establishments by ID and SIC to 1997 to obtain NAICS (6%)

  • -Uncoded establishments of multi-establishment firms based on collective characteristic of all establishments (0.1%)

  • -Random assignment (20%)

  • -Exceptions


Restructuring Retail Time Series Data (cont.)

  • Restated monthly SIC-based estimates from January 1992 – March 2001

  • Restated annual retail estimates from

  • 1992 – 1998

  • Distributions based on SIC to NAICS links developed in 1997 census

  • Adjusted the restated monthly NAICS estimates prior to March 2001 to account for new (NAICS) and old (SIC) based differences


Computing Benchmarked Estimates

  • Restated annual estimates benchmarked to 1992 and 1997 Economic Censuses

  • Minimized differences between the year-to-year changes of the restated annual estimates

  • 1999 was computed using the published 1998 estimate by the ratio of the 1999 to 1998 estimates derived from the 1999 Annual Retail Trade Survey


Computing Benchmarked Estimates (cont.)

  • Monthly Retail Sales

  • For January 1992 through March 2001, restated estimates were changed in a manner that

  • -constrained the sum of the 12 months to equal the benchmarked, restated annual estimate for 1992 through 1999

  • -minimized the difference between the month-to-month changes of the restated monthly and benchmarked series

  • Constant ratio applied to monthly estimates following December 1999


  • Login