PART I - New Seasonal Adjustment Factors for Household Data Series

Employment and Earnings, July, 2001 by Robert J. McIntire

Semiannually, the Bureau of Labor Statistics publishes the factors to be used during the following 6 months for seasonal adjustment of the major labor force series. Table 1 presents the seasonal adjustment factors for the 12 major labor force components for the period July-December 2001. The factors for these components for the first 6 months of 2001 were published in the January 2001 issue of Employment and Earnings. The 12 seasonally adjusted series that result from the application of these factors are used in the computation of the seasonally adjusted figures for the national overall levels of labor force, employment, and unemployment and for the overall unemployment rate.

[GRAPHS OMITTED]

Table 1. Prior adjustment and July-December 2001 seasonal adjustment
factors for the 12 major civilian labor force components

                                        Seasonal adjustment factors

                             Prior
  Procedure and series     adjustment
                            factors     July    August   September

     Multiplicative
       adjustment
    (Divide factor
  into original value)

Agricultural employment:
  Men, 20 years and over       (1)      1.100    1.075     1.058
  Women, 20 years and
    over                      .776      1.094    1.070     1.020
  Men, 16 to 19 years         .860      1.558    1.383     1.051
  Women, 16 to 19 years       .853      1.425    1.527      .983

Nonagricultural
    employment:
  Men, 20 years and over   (2).996,     1.002    1.004     1.000
                             1.003
  Women, 20 years and
    over                    (3).996      .985     .987      .999

Unemployment:
  Men, 20 years and over       .938      .974     .927      .912
  Women, 20 years and
    over                       .976     1.101    1.108     1.011

       Additive
       adjustment
   (Subtract factor
  from original value)

Nonagricultural
    employment:
  Men, 16 to 19 years          -68        723      375      -185
  Women, 16 to 19 years        -96        630      335      -221

Unemployment:
  Men, 16 to 19 years          -47        128      -52       -49
  Women, 16 to 19 years        (1)        105       -4       -12

                             Seasonal adjustment factors

  Procedure and series

                           October   November   December
     Multiplicative
       adjustment
    (Divide factor
  into original value)

Agricultural employment:
  Men, 20 years and over    1.032       .993       .922
  Women, 20 years and
    over                    1.000       .894       .914
  Men, 16 to 19 years        .986       .924       .764
  Women, 16 to 19 years      .986       .670       .630

Nonagricultural
    employment:
  Men, 20 years and over    1.003      1.004      1.002

  Women, 20 years and
    over                    1.006      1.007      1.010

Unemployment:
  Men, 20 years and over     .908       .906       .984
  Women, 20 years and
    over                     .919       .936       .852

       Additive
       adjustment
   (Subtract factor
  from original value)

Nonagricultural
    employment:
  Men, 16 to 19 years        -119       -183        -97
  Women, 16 to 19 years      -159        -77         34

Unemployment:
  Men, 16 to 19 years         -66        -47        -48
  Women, 16 to 19 years        -5         -7       -116

(1) No prior adjustment was done.

(2) For this series, the factors are pre-1997 and pre-1999. The first
factor shows the adjustment of pre-1997 data relative to subsequent
data; the second factor shows the adjustment of pre-1999 data relative
to subsequent data. The actual net adjustment to pre-1997 data is the
product of the two factors.

(3) For this series, the prior adjusted period was
pre-1999 rather than pre-1994.

The new seasonal factors have been extrapolated using the X-11 ARIMA program with data from January 1990 through June 2001 for each series. The ARIMA models used were the same as those used earlier in the year for the extrapolation of the factors for January through June; they were identified in the January 2001 issue of this publication. The historical seasonally adjusted data, including those for the first 6 months of 2001, will not be revised until the beginning of 2002.

Because of the changes introduced at the beginning of 1994, 1997, and 1999 in the survey and the processing procedures on which the labor force series estimates are based,(1) prior adjustment factors were used in these X-11 ARIMA runs to link the pre-1994, pre-1997, and/or pre-1999 data with the subsequent data for purposes of seasonal adjustment. Without prior adjustment, those changes could have caused distortion in the seasonal decomposition. The pre-1994, pre- 1997, and pre- 1999 prior adjustment factors used in these runs were the same as those used in the runs that provided the factors for January through June. The prior adjustment factors for the 12 major components are shown in table 1 alongside the seasonal factors.