Wells Fargo & Co. economists project that holiday sales will increase by 3.7 percent over last year's levels, roughly in line with the National Retail Federation's projected 3.9 percent increase. Although stronger personal income growth should support holiday sales, cautious consumers will keep the pace of spending in check, the company said in its 2013 Holiday Sales Outlook. "Consumers remain reluctant to resume borrowing, especially from credit cards," the economists said. "This reluctance is probably a good indicator of consumers' mistrust of the current, as well as future, economic environment."