Unemployment at 9.2%. The stock market: stagnant. Our national debt load: sagging like a waterlogged ceiling. It's been a long time since Americans had good news to read about their economy. But that just makes Equifax's recent report on U.S. credit trends stand out the brighter by contrast.

Thanks in part to homebuyers reneging on their mortgages, and in part to a renewed reticence to spend-without-end, the ratio of consumers' monthly incomes to their monthly debt payment installments has reached its highest level in 17 years. Loan delinquencies are down 30% over the past two years. Total U.S. household debt declined by $1 trillion in the past 30 months. The final result? The average U.S. consumer's credit score hit 696 (out of a possible 850) in May -- its highest level in four years.

What's it mean to you?
If you invest in companies that cater to the U.S. consumer, Equifax's report is very good news. It means that concerns that crushing debt loads, combined with high unemployment and stagnant wages, will turn consumers into "zombies" incapable of spending on anything more than the bare necessities are perhaps exaggerated.

Last week, we also saw Capital One (NYSE: COF), Citigroup (NYSE: C), and JPMorgan Chase (NYSE: JPM) report strong profits, indicating that banks are flush and at least able to lend. So what happens if these banks start looking at consumers' FICO scores and finding them creditworthy?

These banks could start writing new loans, helping consumers resume shopping sooner than expected. Indeed, a recent Fed survey of bank loans notes increased willingness among America's bankers to vouch for consumers wanting to buy a new car. That could be good news for Honda (NYSE: HMC), Toyota (NYSE: TM), and General Motors (NYSE: GM), which all ranked among the top 10 brands in last month's J.D. Power 2011 U.S. Initial Quality Study. It may be less good news for Ford (NYSE: F), which plunged in the rankings amid customer complaints about its "MyFord Touch" computer interface.

Overall, though, with U.S. auto sales now running 34% below their Year 2000 peak , I'd say if you're looking for a way to invest in Americans' improving credit scores, the automotive sector is a good place to start your search.

Which automaker will take pole position in this race? Add them all to your Fool Watchlist, and find out.

The Motley Fool owns shares of JPMorgan Chase and Ford Motor. Motley Fool newsletter services have recommended buying shares of Ford Motor and General Motors. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Rich Smith holds no position in any company mentioned. Click here to see his holdings and a short bio. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.