It is clear what Sam Walton would do. The founder of Walmart set his company on course to become the world’s largest retailer by using low prices to attract shoppers, and the buying power of those new shoppers to lower prices. Yet, as the company gathers analysts in north-west Arkansas for its annual two-day briefing, investors need reassurance that it is not tied to pursuing sales for their own sake.

The problem is partly one of success. Walmart initially had a good recession, increasing its share of the US market as consumers sought to save money. Yet growth slowed in the second quarter, and its shares, among the few that did not fall in 2008, are down 8 per cent so far this year. Consumers who initially cut back by shopping at Walmart are getting into the habit of thrift – falling basket sizes suggest that they are still trying to reduce spending on discretionary items.