Which do you prefer: An expensive latte or an expensive loan?

Yesterday I heard a terrific presentation from Kevin Volpp, a University of Pennsylvania economist and physician who studies, among other things, how techniques from behavioral economics can nudge people into healthier behaviors. In his talk, to demonstrate how prevalent economically irrational behavior is, he showed a chart comparing growth in Starbucks outlets versus growth in payday lenders.

With the help of Mr. Google, I found the source of the data, which comes from Steven Graves at Cal State-Northridge. Take a look at his chart below.  Are you as surprised as I am?