Board of Governors of the Federal Reserve System

Historical Data: Relative Importance Weights

Documentation: These files include descriptions and the codes that represent the industrial production series in tables 1 and 2.

• Table 1: Industrial Production: Market and Industry Group Summary
• Table 2: Industrial Production: Special Aggregates and Selected Detail
• Relative Importance Weights for Seasonally Adjusted IP (to February 2020).

The relative importance weights provided in the data file allow the user to compute special aggregates of industrial production that are not published in the G.17 release. These weights should be used to combine growth rates of component IP series to obtain a growth rate for a special aggregate.

If industry C is industries A and B combined, the growth of IP for C can be approximately computed using the following formula, where IP_A[t] is the level of IP for industry A in month t and RIW_A[t-1] is the relative importance weight of industry A in month t-1.

IP_C[t]/IP_C[t-1] = (RIW_A[t-1]*IP_A[t]/IP_A[t-1] + RIW_B[t-1]*IP_B[t]/IP_B[t-1])/(RIW_A[t-1] + RIW_B[t-1])

To exclude industry B from IP aggregate A, one would subtract instead of adding:

IP_C[t]/IP_C[t-1] = (RIW_A[t-1]*IP_A[t]/IP_A[t-1] - RIW_B[t-1]*IP_B[t]/IP_B[t-1])/(RIW_A[t-1] - RIW_B[t-1])