How much do migrants cost or benefit a nation? Plus, planning a wedding - when you have friends and family all around the world and a finite number of places at the venue, how do you work out how many invitations to send? Tim Harford speaks to a couple who thought statistics might have the answer.

Chancellor George Osborne says a 50p tax rate does not bring in much revenue; Shadow Chancellor Ed Balls says it does. Tim Harford takes a look at why it is so hard to pin down how much tax is owed by the wealthy. Plus, have wages risen? How much does it cost to raise a child? Who do you invite to your wedding?

Do two large glasses of wine triple your risk of mouth cancer, as claimed on a health leaflet spotted by a sceptical listener? Tim Harford examines the difficulties of extracting smoking from the equation. Surprising as this may seem, one of the world's best tennis players of all time, Roger Federer, is also the worst ranked player on one scale. The scoring system makes it possible to lose a match despite winning more points, and Federer has lost the highest percentage of these types of games. Tim speaks to sports number-cruncher Ryan Rodenberg about why this might be the case.

What does a detailed look at immigration statistics tell us about the benefits, or otherwise, of welcoming overseas citizens? Plus, is it true that by the age of 60, more than twice as many women as men are single, and that older men are often living with younger men? Do two large glasses of wine triple your risk of mouth cancer? And which of the world's best tennis players of all time is also the worst-ranked player in one sense. Tim Harford presents.

An apple-a-day will actually keep the doctors away, according to a study in the Christmas edition of the British Medical Journal. It generated headlines around the world. But were the media right to take the story so seriously? Tim interviews one of the study’s authors and critic Paul Marantz.

Tim Harford discovers that health statistics contradict a report which says obesity is worsening. Plus, he fact-checks: armed police shooting statistics; reports that the UK's had the worst winter storms in 20 years; media reports about controversial Channel 4 programme, Benefits Street; a study that says an apple-a-day really keeps the doctor away.

In Iraq, estimates of the death count since the war started 2003 range from 100,000 to about one million. Tim Harford explores why such a range exists and what methods are used to count those killed during war. Meanwhile he discovers that Iraq's population has been growing strongly over the same period. Plus, mathematician and comedian Matt Parker presents his guide to the imperial measurement system. This programme was first broadcast on the BBC World Service.

Most deaths occur in this week of the year - Tim Harford asks why. He also asks: are there really two million millionaire pensioners in the UK, and how many people have died in Iraq since 2003? Plus, mathematician and comedian, Matt Parker, apologises for his previous apology.

A guide to 2013 in numbers - the most informative, interesting and idiosyncratic statistics of the year discussed by More or Less interviewees. Contributors: Dr Pippa Malmgren, President and founder of Principalis Asset Management; Merryn Somerset-Webb, Editor in Chief of MoneyWeek; Helen Arney, Comedian and Presenter. Producer: Ben Carter. This programme was first broadcast on the BBC World Service.

When the government announced that fees charged by pension providers could be capped, some listeners were sceptical that the benefits could be as great as was being claimed. Tim Harford and Money Box presenter Paul Lewis explain why the numbers do add up. It's claimed that an average of 100,000 Christians die as martyrs every year; Ruth Alexander and Tim Harford fact-check the widely-quoted statistic. Plus, Number Hub mathematician Matt Parker presents his guide to imperial measures; is Britain's railway really Europe's 'most improved'? And when six cyclists died in just two weeks in London, was that a cluster in a random distribution, or a sign that something is systematically wrong with road safety in the capital?