The recession isn't over by any stretch, but we're closer to the end of it than the beginning. It's times like these that managers begin to wonder how they can best position their companies to profit from the eventual recovery. They'd be well off to listen to Darrell Rigby.

For the past 31 years, Rigby has counseled companies like Macy's from his perch as head of Bain & Company's Global Retail practice. He's also the firm's go-to guy for analyzing the impact of downturns, a topic he has studied intently since the Black Monday crash of 1987

Rigby has crisply packaged that knowledge in a new book, Winning in Turbulence, in which he first makes the necessary, if somewhat obvious, observation that each economic downturn affects every company differently. That's because all economic calamities are unique: "It's the same reason why they give hurricanes different names," he quips.

Rigby's larger point is crucial, though: Turbulence is constant. Even in periods of soaring economic growth, he found, about a quarter of all industries are in a downturn. "Even when the recesion ends, turbulence will not," he says.

So if turbulence is a fact of life, how does a company navigate it? Rigby has crunched data on how and why companies improve their position or fall behind during difficult periods. Citing research on retailers during the 2001 recession, Rigby notes that about a third of those companies significantly improved their competitive position amid the chaos, while an equal amount of top performers fell from their perch. "More dramatic gains and losses occur in downturns versus other times," he notes.

Whether a company gains or loses depends on its financial and strategic position going in, as well as its sensitivity to the turbulence: "It's different for Neiman Marcus and for Wal-Mart," he says. "How you behave depends on your position."

Rigby says he's very impressed with how Wal-Mart is dealing with today's turbulence. "They are well aware that they have shoppers in their stores that were not there before the downturn and they would like to make sure that those shoppers, many of whom are higher income customers, will stay with them once economy improves. So they are cutting back on new store openings but making sure their existing store are impressive."

Rigby also likes Amazon's move to acquire online shoeseller Zappos, as well as what CEO Jeff Bezos doing to foster customer loyalty through initiatives like Amazon Prime. Those moves will pay off when the turbulence eases, he feels.

The book also identifies three common "traps" that managers should avoid amid turbulence. One is trying to grow revenue by chasing new customers, some of whom might be more trouble than they're worth. "A lot of times new customers that are only attracted by lower prices will quickly desert you in a recovery," Rigby says. "Ignore them."

He also cautions against what he calls "indiscriminate" cost-cutting. "Obviously you have to reduce costs but if you do so in a way that your core customers notice, that's terrible." Rigby cited General Mills as an example of smart cost cutting, as the soup and cereal maker has simplfied its products and packaging in ways that haven't impacted sales or brand loyalty. And those savings have allowed the company to pump up its ad spending as well.

The final mistake is to curtail customer-focused innovation. "You cannot assume your rivals are cutting back," he says. A smart way to innovate in a downturn is to share ideas (and expenses) with partners, as Procter & Gamble has done over the past decade.