Rare Year-Over-Year Decline For CPI

 | Mar 31, 2015 07:29AM ET

Last week, the BLS reported that headline CPI fell from one year ago. This is primarily because energy prices have fallen. Core CPI (which excludes food and energy) has not registered the same slowdown.

Even though food and energy prices are volatile, it’s rare that a decline in either of those categories will pull CPI changes into negative territory. This is only the 4th period since World War II that consumer prices have fallen vs. where they were a year earlier.

The other times were: the financial crisis (2009), the aftermath of World War II (1949), and a period in 1955–I’m not sure what happened there.

Before WWII, from 1914-1947, CPI only decreased in four additional periods: early WWI (1915), the aftermath of WWI (1921), the Depression (1930-1933) and Depression II (1938).

Since it began measurement in 1958, core CPI has never fallen y/y. It did increase at rates below today’s levels between 1960-1966 though.