How much time will you spend thinking about the next stock you buy? If you're like most Americans, the answer is "not much." According to research from ING, "the average American spends more time researching a new refrigerator than they do stocks."

Now, we all need a good place to keep our beer cold, but that's ludicrous ... and it gets worse.

A recent survey revealed that just 16% of Americans invest according to an asset allocation plan. This means that 84% of us are blindly buying stocks without any regard for what we may or may not already own, or hoping someone else does it right for us!

Why this is bad
In consequence, individual investors get overexposed to certain "hot" sectors. Think back to 2000. Four of the five most widely owned stocks were tied to the Internet bubble -- AT&T, AOL, Lucent, and Verizon. As a result, when the Internet bubble collapsed, investors who owned all of these popular stocks got hit harder than they would have if they had owned some of the stocks that survived the 2000-01 downturn fairly well.

These, however, were industrials, homebuilders, and commodity companies such as Pulte Group (NYSE: PHM), Mohawk Industries (NYSE: MHK), and Arch Coal (NYSE: ACI), all hated at the time because they had wildly underperformed the market during the dot-com boom.

This is why it's important to invest according to an asset allocation plan. Not only will it protect your portfolio from short-term volatility in a specific company, country, sector, or asset class, but it will also help you make more money over the long term as a result.

How to think about asset allocation in 2010
We recently asked our members at Motley Fool Global Gains to review their asset allocation and let us know what they need to gain exposure to in 2010. To help them make that determination, we updated our global asset allocation guidelines. While every individual needs an asset allocation plan tailored specifically to his or her situation, here's how our Global Gains guidelines break down for the typical "aggressive" investor.

  • We want 85% of your investable assets in stocks and 15% in bonds.
  • We want 60% invested within the United States and 40% internationally.
  • Within that international exposure, we want 75% invested in emerging markets and 25% in developed markets.

Some will look at those guidelines and call them overly aggressive. We disagree. They're based on our market outlook and valuation analysis and synthesize the work of top investment minds such as Warren Buffett, Mohammed el-Erian, and Jeremy Siegel. As I've written before, the dollar is doomed and the top markets over the next decade will be currently emerging markets such as China, India, and Brazil.

Is your asset allocation up to snuff?
Unfortunately, Americans today are dangerously underexposed to the rest of the world's markets, with one survey showing that U.S. investors have just 6% of their savings invested outside of the United States. Even our Global Gains members, a very worldly group, are finding that their portfolios aren't yet sufficiently exposed to Africa and Latin America.

What are you missing? I encourage you to find out.

Put your portfolio to the test
When it comes to calculating your foreign exposure, the key is not to look at where the companies you own are headquartered, but rather where they do business. Take Procter & Gamble (NYSE: PG), for example. Although the company is headquartered in Cincinnati, it actually makes more than 60% of its sales abroad. Thus, for asset allocation purposes, Procter & Gamble is better considered a mostly international company.

Similarly, although lululemon athletica (Nasdaq: LULU) is headquartered in Canada, the U.S. now accounts for more than half of the company's sales -- a number that will get bigger over time. Therefore, when it comes to asset allocation, this one is better considered in sync with the U.S.

Now consider the stocks in your own portfolio. Do any of them offer foreign exposure? Do you own any companies that have made doing business in fast-growing China or Brazil an important part of their strategy?

If the answers to these questions are "no," then stocks that do possess these traits are the stocks you need to buy now.

In sum
With an asset allocation plan and additional foreign exposure, your portfolio will be better positioned to profit over the next decade. If you need some help putting those things in place, come join us at Motley Fool Global Gains, where you can find a variety of asset allocation resources, including our updated asset allocation report, as well as dozens of market-beating international stock recommendations.

Click here for more information.

This article was first published Feb. 5, 2010. It has been updated.

Tim Hanson is co-advisor of Motley Fool Global Gains and also needs more exposure to Africa. He does not own shares of any company mentioned. Procter & Gamble is a Motley Fool Income Investor recommendation. The Fool owns shares of Procter & Gamble. You don't need to read the Fool's disclosure policy now, but you can peruse it at your leisure.