Regional Propagation of Business Cycles

Jim Hamilton at econbrowser has put up some interesting gifs that show contagion effects within US states of the business cycles. It's interesting to see the 1985 business cycle caused by a fall in oil prices, which led to both an expansion in most states, but a recession in the oil-producing states, like Texas. That recession, interestingly, then seems to spread to the surrounding states, presumably through inter-state commerce.

One good thing about teaching macro; I actually am interested in the business cycle. More as an observer than an active researcher, though if I could ever get to work with someone on a cycle study, I would jump at the chance. I think it'd be the next best way for me to improve my understanding.