The huge sums that private equity firms make on their investments evoke admiration and envy. Typically, these returns are attributed to the firms’ aggressive use of debt, concentration on cash flow and margins, freedom from public company regulations, and hefty incentives for operating managers. But the fundamental reason for private equity’s success is the strategy of buying to sell—one rarely employed by public companies, which, in pursuit of synergies, usually buy to keep.

The chief advantage of buying to sell is simple but often overlooked, explain Barber and Goold, directors of the Ashridge Strategic Management Centre. Private equity’s sweet spot is acquisitions that have been undermanaged or undervalued, where there’s a onetime opportunity to increase a business’s value. Once that gain has been realized, private equity firms sell for a maximum return. A corporate acquirer, in contrast, will dilute its return by hanging on to the business after the growth in value tapers off.

Public companies that compete in this space can offer investors better returns than private equity firms do. (After all, a public company wouldn’t deduct the 30% that funds take out of gross profits.) Corporations have two options: (1) to copy private equity’s model, as investment companies Wendel and Eurazeo have done with dramatic success, or (2) to take a flexible approach, holding businesses for as long as they can add value as owners. The latter would give companies an advantage over funds, which must liquidate within a preset time—potentially leaving money on the table.

Both options present public companies with challenges, including U.S. capital-gains taxes and a dearth of investment management skills. But the greatest barrier may be public companies’ aversion to exiting a healthy business and their inability to see it the way private equity firms do—as the culmination of a successful transformation, not a strategic error.