Last week's mass-shooting at a cinema in Colorado has - not suprisingly - intensified America's bitter and long-running argument with itself about gun control. The argument is political and highly partisan. But it is also practical: would tighter gun laws actually lead to fewer gun deaths? You might think it's obvious that they would. But it seems the evidence isn't quite that clear. Also: how have Olympians changed in the last century?

The Tour de France, we are told, has finally cleaned up its act and clamped down on the use of performance-enhancing drugs. But if it has, should we expect today’s drug-free riders to be slower than their drug-fuelled forebears? Can statistics tell us whether the Tour de France really is cleaner than it was? Also in the programme: does when you retire influence when you die?

The Tour de France, we are told, has finally cleaned up its act and clamped down on the use of performance-enhancing drugs. But if it has, should we expect today’s drug-free riders to be slower than their drug-fuelled forebears? Can statistics tell us whether the Tour de France really is cleaner than it was? Also in the programme: does when you retire influence when you die?

How much damage did messing with Libor really do to the financial system? And we investigate the claim made by a leading charity that a million British children are "starving".

How much damage did messing with Libor really do to the financial system? After all, most financial trades are two way bets – and for every winner, there is a loser.

Do residents of the tiny micronesian island of Palau really smoke more cannabis, and drink more beer, than anyone else?

What is the highest-earning film ever if you adjust for inflation? And are birthdays killing us?