April 19, 1999
In the 3-month span centered on December 1998, the diffusion index of employment growth among 356 nonfarm industries was 58.1 percent, compared with 71.9 percent in December 1997. The diffusion index of growth represents the sum of industries with increasing employment plus one-half of the industries with unchanged employment as a share of all industries.
Similar patterns appeared in diffusion indexes calculated over slightly longer and shorter time spans. The diffusion index over a 1-month span was 56.6 percent in December 1998, compared to 64.9 percent at the end of 1997. The diffusion index over a six-month span was 56.3 percent in December 1998 and 72.6 percent in December 1997.
Because a diffusion index over 50 percent indicates more industries are gaining employment than losing, but a falling index indicates a narrowing range of employment gains, these patterns may support the conclusion that employment, while still growing, slowed its pace in 1998. In fact, the 2.3 percent gain in employment in 1998 was slightly lower than the average gain of 2.6 percent over the previous 5 years.
Diffusion indexes are a product of the Current Employment Statistics program. For more information, see Employment and Earnings, April 1999, table B-6.