Archive for November 12th, 2008

Math Confusion in the News: percent

November 12, 2008

dollarLast week Governor Arnold Schwarzenegger proposed a temporary (3-year) sales tax increase in California to help close the budget deficit. Some newspapers, however, are mixing up the amount of the increase in an effort to get the news out.

Error #1: “Governor Proposes 1.5 Percent Sales Tax Hike” from MyFox Los Angeles

The proposed increase isn’t actually 1.5 percent (which wouldn’t be all that much). It’s 1.5 percentage points, which makes it about a 20% increase from the current 7.25% state sales tax. I suspect that most people understand what the headline intends, however, because using “percent” instead of “percentage point” is fairly common. (Kudos to the LA Times for being precise in their story!)

Error #2: “Schwarzenegger proposes 1.5-cent sales tax increase to close budget gap” from the San Jose Mercury News

This headline is just wrong. A 1.5¢ tax? And it’s not just in the title, but in the body of the story. Several other newspapers made the same mistake, either running the Mercury News story without correction or writing their own story about the 1.5-cent increase (I’m looking at you, Sacramento Bee). Indeed, these 1.5-cent increase stories were common enough that I actually double checked that it wasn’t some new terminology for “percentage points”.

Incidentally, the word “per cent” is only 440 years old, and “per centage” only 222 years old. Tidbits from the OED!