WSJ: Numbers Guy

The Numbers Guy examines numbers in the news, business and politics. Some numbers are flat-out wrong or biased, while others are valid and help us make informed decisions. Carl Bialik tells the stories behind the stats, in daily updates on this blog and in his column published every other Friday in The Wall Street Journal. Carl, who holds a degree in mathematics and physics from Yale University, also cowrites The Daily Fix, a sports column on WSJ.com. He welcomes your comments at .

WSJ: The Numbers
The Numbers
copyright © 2015 Dow Jones & Company, Inc.
The Wall Street Journal examines the way numbers are used, and abused.

Behind The Numbers: A Busted ‘Time Series’
The Current Population Survey provided reliably comparable data on the number of uninsured Americans--until last year.
Number of the Day: 5.3 Million
Today's number, 5.3 million youth baseball participants, comes at the expense of our national pastime or, some might say, passed time.
Time Check: Markets Fret a Leap Second
As The Numbers wrote in January, the leap second is due to make one of its periodic appearances later this year. And markets are jumpy.
Behind The Numbers: Food for Thought
When it comes to data, the language used to explain is often as important as the numbers. The USDA's estimates of where folks are eating is a prime example.
Numbers Noise: IP Addresses Near Limit
The U.S. is running out of Internet Protocol addresses. But this doesn't mean the Internet has reached its limit.
Number of the Day: $179.4 Million
Today's number, $179.4 million, comes courtesy of the auction house Christie's, which on Monday evening sold Picasso's "Women of Algiers (Version O)" to an anonymous telephone bidder.
Numbers of the Week
Every day this week will be the same forward and backward, if formatted as it is in the U.S. as 5/11/15 (i.e., 51115, 51215, etc).
Numbers Game: 2, 3, 4, 5 = 18 (But How?)
Take the numbers 2, 3, 4, 5, use any combination of addition, subtraction, multiplication and division and arrive at an answer of 18.
Behind The Numbers: Scoring on the SAT Score
Professional test-prep courses are time-consuming and expensive, but if they significantly boost a student’s SAT score, they might be worth it for those who can afford the coaching.
Reader Mailbag: Minding the GAAP
When financial sources report price per earnings ratios, do they use GAAP earnings?