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How much more scrutiny do boards of directors face these days? By one measure, a lot more: the number of activist investor deals rose 34% between 2000 and 2014. According to Bain & Company’s analysis, activist investors are now the fastest-growing class of institutional investors—and more than 75% of their demands involve nominating or replacing directors on boards.

For directors, this is simply a fact of life, and the best way for a company to avoid activist attention is simply to deliver the fundamental performance that leads to long-term value creation. A company that creates a sustainable competitive advantage, executes well and reinvests to solidify its strategy will find that its share price accurately reflects its value. And if there is no arbitrage to be had, most activists will hunt elsewhere.

So how can boards ensure their company is able to grow sustainably? In research for our book, The Founder’s Mentality, my coauthor and I found that 85% of the time, the barriers to sustainable growth are not external, but internal, and include bureaucracy, ability to motivate and retain talent, and slowness to decide, act or redeploy. Among the largest companies, executives cited these barriers 94% of the time.

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Founder's Mentality

Fast-growing companies can become global leaders without losing the values that helped them succeed. Bain’s research explores how large incumbents can also reignite their growth by recapturing their Founder’s Mentality®.

Our research also found that most major reversals of highly successful companies began because the company lost the very culture responsible for its original success. As any director who has worked with a successful founder knows, great founders instill their companies with common traits: A sense of insurgency on behalf of customers, an obsession with the front line, and an owner’s mindset that hates bureaucracy and views every dollar as potential funding for innovations that will serve customers even better.

Even—or perhaps especially—if the founder is long gone, these traits should be top of mind for boards of directors. Their loss often presages external failure.

Consider how Home Depot, born of two founders, stumbled when its board hired Bob Nardelli from General Electric to be CEO and instill big-company discipline. He did, but he also diversified from the core, substituted cheaper clerks for expert staff and cut, among other costs, the bonus pool for frontline excellence. When Home Depot slipped to last among U.S. retailers in customer satisfaction and its market value declined by 55%, the board stepped back in, meeting with employees and learning how to restore the company’s original focus on a close, advisory relationship with customers. They then brought in a CEO who unwound the diversifications and invested in the stores, requiring senior executives to work in stores each month, rehiring expert staff, and bringing back special awards for heroic performance by store employees. Today, the company has regained its mojo.

Or take TNT Express, a vibrant Australian business with a strong founder’s mentality that grew into one of the two top delivery services in Europe. In 1990 the Dutch national postal company, KPN, purchased TNT and installed a CEO with a financial background who built a gigantic corporate headquarters far from operations, and invested cash away from the core. When CEO Tex Gunning took over in 2013, he spent weeks in depots and on trucks and wrote to every frontline employee asking for input. He found a company that had suffered years of neglect in the human fabric that once had been its strength. TNT’s acquisition in May by founder-led Federal Express suggests a happy ending, but TNT’s internal erosion was avoidable.

The lessons for directors: Lose your insurgency and you lose the ability to inspire, create internal energy, and attract and retain the best young talent. Lose the frontline obsession and you lose your ground-level instincts and run the risk of getting out-hustled by insurgent competitors. Lose an owner’s mindset and leaders turn into managers, then custodians and, ultimately, bureaucrats.

Our research shows companies that preserve these traits are four to five times more likely to be top performers than those that do not. And boards can monitor them. Is the insurgency still strong? If so, any employee should be able to explain the “strategy on a hand”—that is, on thumb and fingers, list the company’s special purpose and four unique capabilities that support it. A simple acid test of the distance between leaders and the front line is how much time senior management actually spends in the field or with customers. Boards can detect burgeoning bureaucracy by looking at which direction headcount and decision power are flowing.

Finally, boards should be highly attuned to speed. Are younger insurgent companies faster to launch products, to innovate, to react to customers? A simple, independent review of which companies introduced the last 10 major innovations in the industry will be telling here.

Boards are responsible for the long-term health of a company. Those that regularly ask, “Do we have the founder’s mentality?” can help preserve it.

Chris Zook is a partner in Bain & Company’s Boston office and has been a co-head of the firm’s global strategy practice for twenty years. He is a co-author of a number of bestselling books including Profit from the Core and The Founder’s Mentality: How to Overcome the Predictable Crises of Growth (Harvard Business Review Press, June 2016).