Friday, February 19, 2010
This morning's inflation report is generating all sorts of headlines about core consumer prices falling for the first time since 1982. In looking at the screen shot of the detailed data from the Labor Department below, there is clearly some sort of a math problem associated with changes that were recently made to category weightings (note that only the relevant data is included below from a much larger table).
Looking at the weighting (Relative importance) and the indentation on the left to determine which categories are sub-categories of others it becomes clear that you can't get the large negative number of -0.5 percent circled in red from the data circled in blue.
It appears that they are mistakenly weighting the -2.1 percent decline for lodging away from home at a much higher level and, since housing is a major component of core inflation, the first negative reading in 28 years was the result.