More than 7 million light trucks were sold in September, which was the highest monthly sales count for trucks in 3 and-one-half years going all the way back to March of 2008 (see chart above). September truck sales were up by 9.5% compared to August and up by 20.3% compared to last September. Why are truck sales important?

Mark Perry, professor of economics and finance at University of Michigan, thinks so.