I wonder how many people had to read this correction twice, as I did:
A driver who texts while driving is six times as likely to be involved in a crash as a driver who doesn't text. A Business News article Saturday about driver-monitoring systems incorrectly said that a driver who texts is six times more likely to be involved in a crash than one who doesn’t.When I got it — the Wall Street Journal had written “six times more likely,” and now was “correcting” the wording to “six times as likely” — I knew it was meant for a small band of sticklers. These are the people who claim that “six times as likely” means “multiplied by six,” but “six times more likely” really — that is, properly, mathematically — means “multiplied by seven”: It’s the original amount plus six more servings.
But I don’t buy it. As Merriam-Webster’s Dictionary of English Usage says, “It is possible to misunderstand times more in this way, but it takes a good deal of effort.” In real life, nobody uses “six times more” to mean “seven times as much” (and if they did, how would a reader know it, without the numbers?). MWDEU concludes:
The fact is that “five times more” and “five times as much” are idiomatic phrases which have — and are understood to have — exactly the same meaning. The “ambiguity” of times more is imaginary.
The same argument is aimed at “six times less” to mean one-sixth — which, unlike “times more,” often does trigger my editorial antennae. I’d consider changing it in copy, if it were at all distracting. But I stopped worrying about it once I noticed that Mark Liberman of Language Log uses it unapologetically, even in contexts where he’s wrangling complicated statistics. If it’s OK with him, it’s OK with me.
Motivated Grammar defends “times less”: https://motivatedgrammar.wordpress.com/2008/11/10/five-times-dumber/
My Globe column on “times less”: http://archive.boston.com/news/globe/ideas/articles/2007/10/21/do_the_math
John McIntyre disagrees, gently: http://weblogs.baltimoresun.com/news/mcintyre/blog/2008/10/less_is_not_more.html
Bill Walsh disagrees, firmly: http://www.theslot.com/times.html
Arnold Zwicky treats “times more” and “times less” in a post on the Recency Illusion: http://languagelog.ldc.upenn.edu/nll/?p=463