The CPI numbers for April were released by the Bureau of Labor and Stastics (BLS) today. All CPI data also can be retrieved from FRED, Federal Reserve Economic Data, which is where I get them from. The CPI all urban consumers not seasonally adjusted (CPIAUCNS is the FRED designation) value for April is 313.548. This is a 0.39% increase over March (= 313.548/312.332-1), and a 3.36% increase over April 2023 (year over year or YoY).
The April CIPAUCNS sets the TIPS reference CPI, used for TIPS inflation adjustments, for July 1. The TIPS daily inflation adjustment for each day from June 2 to June 30 are calculated as the linear interpolation between the ref CPI values for 6/1 = 312.332 and 7/1 = 313.548. So the ref CPI is for 6/2/2024 is 312.37253 (=312.332 + 1/30 * (313.548-312.332); the value is rounded to 5 decimal places.
The .39% total inflation adjustment for June is an annualized inflation adjustment rate of 4.77%. As if often noted, not too much should be read into the adjustment for a single month, since inflation adjustments are volatile. A seasonally adjusted CPI value (CPIAUCSL) also is released, and for April it was 313.207, which compared to March = 312.230 is a 0.31% increase, which is a annualized increase of 3.82% (and YoY increase of 3.36%, same as for the NS YoY increase). Seasonal adjustments remove the well known and quite regular seasonal affects on CPI.
To illustrate all of this, here is a chart of NS and SL CPI value vs month:
![Image]()
Note that the CPI changes for the first half of the year are generally lower than for the second half of the year, which is typical. Thus, the seasonally adjusted values (SL) tend to be lower than the NS values for the first half and higher for the second half of the year.
Here is the same chart, but showing ref CPI date on the X axis:
![Image]()
As explained above, for example, we see the April 2024 CPI values as the 7/1/2024 reference CPI values.
BLS also releases seasonal factors each February. These are calculated as NS/SL * 100, and can be used to seasonally adjust TIPS yields. Viewing a chart of NS/SL provides insight into the regularity of the impact of seasonality of the CPI:
![Image]()
The ratio of the seasonal adjustment (SA) factors for the settlement date and TIPS maturity date can be multiplied by the TIPS unadjusted price to calculate a seasonally adjusted TIPS price, from which a SA yield can be calculated, and I often post charts of the unadjusted and adjusted TIPS yields.
The April CIPAUCNS sets the TIPS reference CPI, used for TIPS inflation adjustments, for July 1. The TIPS daily inflation adjustment for each day from June 2 to June 30 are calculated as the linear interpolation between the ref CPI values for 6/1 = 312.332 and 7/1 = 313.548. So the ref CPI is for 6/2/2024 is 312.37253 (=312.332 + 1/30 * (313.548-312.332); the value is rounded to 5 decimal places.
The .39% total inflation adjustment for June is an annualized inflation adjustment rate of 4.77%. As if often noted, not too much should be read into the adjustment for a single month, since inflation adjustments are volatile. A seasonally adjusted CPI value (CPIAUCSL) also is released, and for April it was 313.207, which compared to March = 312.230 is a 0.31% increase, which is a annualized increase of 3.82% (and YoY increase of 3.36%, same as for the NS YoY increase). Seasonal adjustments remove the well known and quite regular seasonal affects on CPI.
To illustrate all of this, here is a chart of NS and SL CPI value vs month:
Note that the CPI changes for the first half of the year are generally lower than for the second half of the year, which is typical. Thus, the seasonally adjusted values (SL) tend to be lower than the NS values for the first half and higher for the second half of the year.
Here is the same chart, but showing ref CPI date on the X axis:
As explained above, for example, we see the April 2024 CPI values as the 7/1/2024 reference CPI values.
BLS also releases seasonal factors each February. These are calculated as NS/SL * 100, and can be used to seasonally adjust TIPS yields. Viewing a chart of NS/SL provides insight into the regularity of the impact of seasonality of the CPI:
The ratio of the seasonal adjustment (SA) factors for the settlement date and TIPS maturity date can be multiplied by the TIPS unadjusted price to calculate a seasonally adjusted TIPS price, from which a SA yield can be calculated, and I often post charts of the unadjusted and adjusted TIPS yields.
Statistics: Posted by Kevin M — Wed May 15, 2024 11:55 am — Replies 0 — Views 128