Are there 21 million slaves in the world today?
Is it possible to become an expert on practice alone?
How quickly will the online global drinking craze Neknomination spread - and fizzle out?
The maths behind modern matchmaking
Deaths from drug overdoses in the United States are on the rise – but why?
Tim Harford explores the economic benefits of immigration, plus wedding guest strategies.
Do two large glasses of wine triple the risk of mouth cancer?
A study has shown an apple-a-day will actually keep the doctors away but is it accurate?
How do you count those killed in war accurately?
The most informative, interesting and idiosyncratic statistics of the year