More or Less: Behind the Stats - The maths of spies and terrorists

After the killing of a British soldier on the streets of Woolwich in London, it emerged that the suspects were known to the security services. But how feasible is it for the authorities to keep track of everyone on their watch list? Tim Harford crunches the numbers, with the help of the former head of MI5, Dame Stella Rimington. Plus: a listener requests a cost-benefit analysis of kidney donations; and Johnny Ball gives the Apprentices a maths lesson.

Start the Week - Eric Schmidt on the New Digital Age

On Start the Week Emily Maitlis talks to the Executive Chairman of Google, Eric Schmidt about the digital future. A future where everyone is connected, but ideas of privacy, security and community are transformed. Former Wikileaks employee James Ball asks how free we are online. The curator Honor Harger looks to art to understand this new world of technology. And worried about this brave new world? David Spiegelhalter, offers a guide to personal risk and the numbers behind it.

Producer: Katy Hickman.

More or Less: Behind the Stats - The economics of Scottish independence

Tim Harford inspects the claims the UK Treasury and the Scottish government make about the economics of an independent Scotland; tests Ryanair?s claim that more than 90% of its flights land on time; re-runs the Eurovision song contest, excluding the votes of the former Soviet countries to test whether political alliances are affecting the final results; discovers that millions of scientific papers may be incorrect; and learns more about dog years ? and cat years.