Some things change. Others don't.

Costs matter. This is one of the eternal verities of investing. We know this from John Bogle, the founder of Vanguard and patron saint of index investing. If we act on this simple fact, we can improve our investment results.

This isn't what Wall Street tells us.

The investment community tells us that only their constant attention, their cadres of MBAs and Ph.D.s, and their special knowledge of the world can lead us to good returns.

They intimate that the more we pay them, the more likely we will get superior performance. They spend millions of dollars on advertising to convince us.

Alas, it isn't so.

A simple exercise with the cost factor, however, can improve our results. Let me demonstrate.

At the end of May there were 194 mutual funds that Morningstar categorized as "moderate allocation," or balanced, funds with at least five-year histories.

These funds are typically a 60/40 mix of equities and fixed income. Their annualized return over the past five miserable years was 0.94 percent. Their average net expense ratio was 1.17 percent. The top 25 percent of funds by expense cost at least 1.35 percent to manage, averaged 1.8 percent in expenses and produced an average return of 0.21 percent.

If you selected from this group at random, hoping that high expenses would buy better management, you had only a 32 percent chance of doing better than average.

If you went in the other direction and chose from the 25 percent of funds that were least expensive, costing 0.88 percent or less a year to manage, the average return was 1.4 percent a year. You had a 55 percent chance of beating the average for the category.

In other words, you've got a better shot — not a guaranteed shot, just a better shot — at superior results if you insist on lower expenses.

And there is a better way. Marketwatch columnist Paul Farrell calls it the "lazy portfolio" way.

Years ago he started reporting on the performance of do-it-yourself portfolios that could be built with low-cost index funds.

These portfolios range from some of my Couch Potato portfolios to Bill Schultheis' "Coffeehouse" portfolios, William Bernstein's "Coward's Portfolio" and David Swensen's "Yale Model" portfolio.

Eighteen months ago, I showed that 11 of 14 balanced "lazy portfolios" beat the average for all balanced mutual funds over the preceding three years. So taking the lazy way out gives you a 79 percent chance of beating the category average.

What does this mean for you and me? It means don't be afraid.

The reality is that if you choose just about any "lazy portfolio," the odds are that you will do better than if you choose the more expensive alternatives.

Would you like certainty? Yeah, so would I. But there is no certainty. All we can do is search for the best odds.

Questions: scott@scottburns.com