Value investors have had a rough decade.

For the past 10 years, the Russell 3000 value index has underperformed the Russell 3000 growth index by 3 percent a year, said Alex Bryan, Morningstar’s director of passive strategies research. Despite this, panelists at a Morningstar session on value investing said that this stretch of subpar performance is not a sign that value investing is dead.

Ronen Israel, a principal at AQR Capital Management attending the Morningstar Investment Conference in Chicago Thursday, said the 10-year underperformance does not make him question the value investing concept.

“There are different types of value measurements,” he said. “Value as a strategy, long term, is a good strategy. But it doesn’t make money all the time. It’s not unusual to have a period of underperformance like what we’ve just seen. You have to keep in mind these are long-term, good strategies and be willing to accept times of underperformance.”

There are strong economic drivers that make value investing work, he said. Some of those drivers are risk-based and some are behavioral. And he doesn’t see them going away.

“Ten years isn’t enough time to judge it,” Israel said.

John West, head of client strategies at Research Affiliates, said people are focused on having good short-term returns and less on the big picture, which makes it difficult to embrace value investing.

“People understand it; they believe in the value effect, but they just can’t follow through because they don’t want to report it to a fiduciary, [who might say] ‘You bought what? And it went down and you bought more?’ That’s a very difficult thing to do from a psychological perspective,” West said.

Jared Watts, a portfolio manager at Morningstar Investment Management, said the value premium is real, but the way of capturing it eludes a lot of investors.

“It’s proven to be more structural in nature. As long as fear and greed exists, there will be a value premium,” Watts said.

Watts and Israel said combining other factors with value can help diversify a portfolio and prevent investors from falling into value traps. Watts said quality is a good factor to complement value.

For example, if an investor used only a value measure, like price-to-book, during 2007 and 2008, that person would have bought financial stocks, which had lost 22 percent in the preceding period. But a quality screen used in conjunction with value would have shown that measurements like mortgage quality, leverage and other metrics were grossly out of line, helping the investor avoid the purchase.

Israel said advisors can look at the idea of value broadly. There is the simple stock-to-stock comparison, but it’s also worthwhile to compare industries and even markets when thinking about value investing.

Advisors who use these complementary measures and look with greater breadth will be able to explain to clients why value investments make sense.

“Education is important,” Israel said. “You have to understand what you’re investing in. It’s a good long-term point of return, but you have to stick with it. It’s not just about the empirical, but also the theory.”

Advisors may need to explain the justification in other terms. For instance, Israel said, investors believe in the long-term returns of the stock market, even during times of subpar performance. The same should be true for value investing.

West agreed.

“Clients must understand that they need to be in the portfolio for a long time. They can diversify to an extent, but they need to go through the same rationale [they use in value investing] to believe in those [diversifiers]. They have their own issues and underperformance.”