The CPI-U. A measure of the rate of change in the overall price of a fixed basket of goods and services from month to month. The premier measure of inflation in the United States.
March CPI was nowhere near as bad as February. CPI-U was up 0.5% (right in line with expectations), with the "core" CPI-U rising only 0.1% (beating expectations). Food rose 0.8%, with "food at home" rising 1.1%, and energy rose 3.5%. For the rolling 12 months ending March 2011, CPI-U is up 2.7%, with food at home up 3.6% and gasoline up 27.5%, The Econoday-surveyed analysts are expecting April to be even better, calling for a 0.4% increase in CPI-U and a 0.1% increase in "core" CPI-U.
As is our wont, we turn to the US Bureau of Labor Statistics for the Consumer Price Index Summary to see if those analysts were right. And, in a nutshell, they were half right. CPI-U increased 0.4% in April (as expected), while core CPI-U increased 0.2% (missing expectations). The energy index rose 2.2% (with gasoline up 3.3%), while the food index increased 0.4% (with food at home increasing 0.5%). And for the rolling year, CPI-U is up 3.2%.
 More formally, the Consumer Price Index for All Urban Consumers.
 Of course, "fixed" is a relative term. Obviously, the contents of the basket will change over time. After all, when was the last time your household had to concern itself with the increasing costs of buggy whips or typewriter ribbons? More interestingly, what components of the basket are considered "core" also change from time to time.