Industry consolidations have greater market success if managers of the acquired companies remain involved in the business, a U-M business researcher says.

“If the managers and owners of the firms included in the transaction remain involved in the business as shareholders and directors, both operating and stock-price performance improve and future acquisitions are better received by the market,” says Amy Dittmar, assistant professor of finance at the Stephen M. Ross School of Business.

In contrast, higher ownership by the sponsor of the transaction leads to a reduction in performance, in large part because the sponsor’s compensation often is excessive and drains wealth from the newly formed entity, according to Dittmar and colleagues Keith Brown of the University of Texas and Henri Servaes of the London Business School.

In a study forthcoming in the Review of Financial Studies, the researchers examined 47 service-sector, construction and durable-goods wholesale firms that engaged in roll-up initial public offerings (IPOs) between 1994 and 1998, in order to determine what type of corporate-governance structure is most successful in delivering shareholder value. Roll-up IPOs are transactions in which a shell company goes public while simultaneously merging with other firms that operate in the same industry.

They found that long-run stock-price performance is higher when a greater number of the roll-up firm’s directors come from the founding companies. Specifically, there is a 2.8 percentage point increase in returns for every percentage point increase in the fraction of directors who are founders.

In addition, roll-ups perform better if the original founders own more shares of the new company at the time of going public, the study shows.

Although the average accounting performance of the roll-up firms in the study is not worse than industry benchmarks, their actual earnings generally fall far short of investors’ expectations and analysts’ forecasts, the researchers say.