More Than Half Of All Mega-Mergers Disappoint Investors. Why Are They Booming?

Anheuser-Busch InBev's massive deal to acquire SABMiller would bring 30 percent of the world's beer market into one firm and comes in a year that is on track to rival 2007 for the highest value of mergers and acquisitions on record. But as CEOs jostle to join the party, experts in dealmaking warn that success is hard to come by. "More often than not, these things don't deliver what people expected at the outset," said Andrew Waldeck, a partner at the global consultancy firm Innosight.