Earlier this summer, economists at the Bureau of Labor Statistics released a new series of the Consumer Price Index. While improvements to the CPI-U make the present and future CPI more accurate, the historical price index series are not adjusted to reflect these changes. To meet demand for a series that's consistent over time, BLS economists designed the CPI-U-RS, which attempts to answer the question, "What would have been the measured rate of inflation since 1978 had the methods used to calculate the CPI-U today been used in the past?" The economists found that, over the 21-year period of the study, the CPI-U-RS increased 141.2 percent, compared with 163.9 percent for the CPI-U. These figures represent an average annual increase of 4.28 percent for the CPI-U-RS and 4.73 percent for the CPI-U. The BLS encourages anyone who is tracking economic trends to use the CPI-U-RS.