This means that a switch to geometric mean CPIs usually leads to higher measured growth rates of output and productivity. Average annual growth rates of output and productivity for periods beginning in 1992 generally have been revised upward for most retail trade and services industries due to the use of geometric mean CPIs, with the typical revision being less than 1.0 percentage point. These revisions should be kept in mind when comparing labor productivity data for years before and after 1992. It is likely that, if the geometric mean CPIs were available back to 1987, productivity growth rates would also be revised upward for 1987-92 for many industries. The attached tables show the effects on the growth rates of output and labor productivity of switching to geometric mean CPIs for all retail trade and services industries for which BLS publishes labor productivity statistics.
Labor productivity is measured as output per hour.
Table 1 shows the effects on output and productivity growth rates of switching to geometric mean CPIs for the period 1992-96. That is, the table shows the overall revisions in previously published output and productivity measures that are due to the incorporation of the geometric mean CPIs. Note that BLS has not made any adjustments to output or productivity series for years prior to 1992 based on the incorporation of geometric mean CPIs. Data users interested in making a simple adjustment to output and productivity series for years prior to 1992 using data on revisions for the 1992-96 period should be aware of the following. Further, improved estimates of quantity weights for item substitution were introduced in July 1996.