Nicholas Gruen once told me that there are two types of economists in the world – those who don’t believe there are $20 bills lying on the footpath, and those who pick them up. As a firm believer in the efficient markets hypothesis, I was therefore somewhat concerned when I picked up a friendly-looking orange note on Grattan Street today.
(And yes, I had a witness.)
Andrew Leigh's Archived Blog 2004-2010 
My then girlfriend and I found $180 lying on Toowong High Street in 2002. And we’re sociologists!
About $200 at Currumbin Sanctuary last year. Sadly, though, we decided we couldn’t ignore the panicked looking woman running backwards and forwards along the path. I think this must mean I’m a really bad economist.