The mood of frugality that has led US consumers to seek out discount retailers such as Wal-Mart and Costco has increasingly spread to the affluent and wealthy, according to a survey of attitudes in some of America’s richest households.

The research, based on interviews with 625 respondents who represent the wealthiest 10 per cent of US households, found that 80 per cent said they were looking closely at every spending category to see where they could save – up from 68 per cent in April.