Looking across spending as a whole in 2008, we can see a phase change beginning in the summer. After a bump in the May/June time frame from tax refunds and credits, we see spending declined by $400 / month / household. Spending eroded even further (a $200 drop) in November along with consumer confidence, bouncing back only slightly for the holidays.
After the market close today, American Express announced its financial results for the fourth quarter of 2008.
Overall Amex cardholder spending declined 10% year over year - or 5% when adjusted for foreign exchange rates. In the US, card billed business (including cash advances) declined 8% year over year, falling from $123 billion to $112.7 billion in the fourth quarter 2008. In terms of average cardholder spending, Amex reported it declined 15% to $2,792 for the quarter. The average merchant discount rate remained essentially unchanged at 2.53%.