DETROIT (AP) — Take a step back from the picked-over store shelves, the stalled container ships and the empty auto showrooms, and you’ll find a root cause of the shortages of just about everything you’d want to buy.

We’re buying too much stuff. Households flush with cash from stimulus checks, booming stock markets and enlarged home equity have felt like spending freely again.

And since consumer demand drives most of the economy, the recovery keeps sailing ahead. Add the fact that companies are ordering more goods and parts than they need so they don’t run out, and you end up with an almost unquenchable demand that is magnifying the supply shortages.