What gas prices do — and don’t — tell us about the economy

Gasoline is the only product in modern-day America whose price is listed on giant signs almost everywhere you go. Most people, even if they don’t drive, probably have a pretty good sense of what gas costs — currently averaging $5 a gallon nationwide.

The ubiquity and visibility of gas prices make them an easy shorthand for the rest of the economy, especially when they’re going up. And they often drive how people are generally feeling about the state of the economy and politics.

But gas prices aren’t really the best metric for understanding...