Economics is all about consumption. People either spend money now or they use financial instruments — like bonds, stocks and savings accounts — so they can spend more later. A healthy economy is largely a result of a reasonable balance between consumption today and consumption deferred, and it’s pretty clear that balance has been ridiculously out of whack for a while.

Our current problem is that much of the world has shifted rapidly from consuming way more than it could afford to consuming far less. The subsequent whiplash has left many people (and, in some cases, entire countries) broke, unemployed and deeply pessimistic about the future. And while we can measure stock prices and bond rates, the key factor that determines consumption and, therefore, the health of the economy, lies in our psychology. Economists believe that what we feel about the state of the economy is best revealed not through what we say in surveys but rather through what we buy and exactly how much of it. There’s a lot of data available, though none come with a prepackaged psychological narrative attached. So analysts do the best they can, combing through our national shopping lists hoping to uncover clues. Sometimes they find remarkably helpful information in very unlikely places.

They also uncover plenty of cute facts that mean little. Consider this: 2011 was a banner year for the sale of insanely expensive fine wines at auction. Someone at a Christie’s auction in Hong Kong, for example, bought 12 bottles of 1985 Romanee-Conti for a bit more than $150,000, or about $600 per sip. And the grand lesson this teaches us about the overall economy is . . . absolutely nothing. There’s some meaning in this anecdote about how the superrich — especially the newly superrich in China — are doing far better than the rest of us. But that can’t help us figure out if we’re headed for a double dip, a stagnant decade or a sudden rebound.

To figure out what our buying behavior says about the U.S. economy’s future, we have to understand what’s going on in the middle class, the 50-percenters. And to figure this out, my colleagues and I at NPR’s “Planet Money” went searching for as many shopping-based indicators as we could find, hoping some would unlock a hidden story about what Americans are feeling and where the country is headed.