More evidence of middle class economic pain

Wal-Mart shoppers, a category that includes 90% of Americans, are increasingly living paycheck to paycheck. Spikes in sales just after paydays are growing more pronounced and now, for the first time, are showing up in sales of baby formula. The information is in a speech by a senior Wal-Mart executive to be given today at Town Hall Los Angeles, as reported by Reuters and picked up by Mark Thoma here.