Trick or treat and other traditions are now at the centre of a global multi-billion business. The ancient Celtic and Pagan festival, which started thousands of years ago in Ireland, was taken by emigrants to North America, where it was turned into a major annual event. The National Retail Federation in the US tells Russell Padmore how spending by consumers is forecast to be a record of more than $12bn. Jadrain Wooten, an economist at Virginia Tech, says the sales promotions for Halloween are getting earlier every year and lasting at least month. We hear about the economic benefits of Europe’s biggest Halloween Festival in Derry City in Northern Ireland and visit a pumpkin farm in the region. An Irish cultural historian, Manchán Magan, tells us about the roots of the festival, which used to be called Samhain and we find out how retailers in Australia are cashing in by selling costumes, pumpkins and other items as consumers enjoy the traditions of Halloween.Presenter: Russell Padmore(Image: Children trick or treating in the North East of England. Credit: Getty Images)