How harmful is alcohol?

New alcohol guidelines were issued recently which lowered the number of units recommended for safe drinking. But are the benefits and harms of alcohol being jusged correctly? We speak to Professor David Speigelhalter and Sepsis – do 44,000 people die of it a year? Is it the country's second biggest killer? We speak to Dr Marissa Mason about the difficulties of knowing the numbers. Dan Bouk tells the story of a statistician who crept around graveyards in South Carolina at the turn of the century recording how long people lived - all to help out an insurance firm. It's from his book 'How our days became numbered' – looking at how data from insurance company has shaped knowledge about our lives. Have refugees caused a gender imbalance in Sweden or is there something funny going on? It has been reported that there are 123 boys for every 100 girls aged between 16 and 17 in Sweden. In China, the ratio is 117 boys to 100 girls. We explore if the numbers add up and why this might be. Presenter: Tim Harford Producer: Charlotte McDonald