FRED includes consumer price index data from the US Bureau of Labor Statistics. FRED data tools make it easy to use these price data to calculate the dollar value of figures measured at constant prices—a process known as adjusting for inflation.
The FRED Blog frequently adjusts for inflation when describing prices, whether it’s gasoline prices, stock prices, or foreign exchange (just to name a few data series).
The FRED graph above shows two versions of monthly advance retail sales of retail trade and food services, reported by the US Census. The blue line shows the dollar figures unadjusted for inflation, and the red line shows the dollar figures adjusted for inflation with the aforementioned consumer price index (CPI). The CPI currently uses the years 1982-1984 as the reference period, so you can think of the data shown by the red line as retail sale figures measured in 1982-1984 prices.
FRED makes it easy to customize the reference period to adjust dollar figures for inflation. So, read on!
The second FRED graph above shows the same advance retail sales series as the first graph, but adds two alternatives using customized reference periods: the start of the 2001 recession (the dashed-dotted red line) and the start of the 2020 recession (the dashed red line). The steps for creating that graph are listed below.
A benefit of customizing the reference period, by choosing a more-recent date, is to facilitate the visual comparison between the inflation-adjusted and unadjusted data. And, given that the choice of reference period does not impact the calculation of the rate of growth of inflation-adjusted data, you can be confident using those units to tell the real story behind the numbers.
How the graphs were created: First graph: Search FRED for and select “Advance Real Retail and Food Services Sales.” Use the “Edit Graph” panel to select the “Add Line” tab and search for and add “Advance Retail Sales: Retail Trade and Food Services.” Second graph: Add another line for “Advance Retail Sales: Retail Trade and Food Services” and customize the data by searching for “Consumer Price Index for All Urban Consumers: All Items in U.S. City Average.” Don’t forget to click “Add.” Next, type the formula (a/b)*100 and click “Apply.” Edit the “(b)” series in Line 2 by changing the units to “Index (Scale value to 100 for chosen date)” and selecting a date of your choice. Finally, repeat these last steps with a new line, searching for “Advance Retail Sales: Retail Trade and Food Services” and selecting a different date. You can also use the “Format” tab to play with the color and style of the lines.
Suggested by Diego Mendez-Carbajo.
