THRIFTY shoppers do not have to look far to find a bargain. Offers abound in the cut-throat world of British supermarkets. Received wisdom suggests that people trying to save money on their groceries should shop around to get the best prices. But research presented on April 9th at the Royal Economic Society suggests that those who do so end up paying more.
Kun Tian, a researcher at Cardiff Business School, and Ji Yan of Durham University, the paper’s authors, argue that people who buy all their groceries at just one of the big supermarkets (Tesco, Sainsbury’s, Asda and Morrisons) pay less than those who purchase equivalent goods at a mixture of the four of them. Data from Kantar Worldpanel, a market-research firm, show similar trends. Unlike Mr Tian’s study, these cover total purchases rather than comparing equivalent baskets of goods. They show that people who bought groceries in just one store during the 12 weeks to September 2013 spent £631. Those who went to ten different places, by contrast, forked out £1,249.