There's a simple reason why Paris Hilton will never hold the keys to the family empire: The Hiltons don't own it.

Barron Hilton, second son of hotel genius Conrad Hilton, sold the business to the Blackstone Group for $26 billion in July 2007, bypassing his eight children, including Paris' dad, Rick. The heirs were not apparent.

A recent study of 242 family businesses owned by ultra high-net-worth individuals commissioned by U.S. Trust, Bank of America Private Wealth Management shows that despite professing dedication to preserving wealth, these companies are not doing the planning--estate, succession, asset protection--to achieve it.

Only 15 percent of the companies studied stay under the control of their founding families past the second generation. Pressures exerted by other family members--whether a battle for control or because an individual is out of control--correlate to a surprising lack of planning.

Two-thirds of these uber-rich business owners want to keep it in the family and have a succession plan. Only one-third of those plans are being implemented, and most of them are out of date.

"The thing about the rich is that everybody thinks they have it all put together, but they're not even close," Russ Alan Prince, a world authority on private wealth and co-author of the study, observes. "They're too busy making money to protect the money they're making."

Protecting the Family Fortune is a behavioral study based on psychographics. It segments family businesses into those that are "business-focused" (that is, they put the business first in making management decisions) 37.6 percent) and family-focused (which put family members' needs first).

The sample included privately held businesses valued in excess of $300 million.

Family-focused businesses, which make up almost two-thirds of those surveyed, are much less likely to have succession plans that are business-focused firms, which comprise the rest of the survey.

"People forget that being rich doesn't insulate them from everyday life," Prince says. "This is endemic of the entire planning population. You're surprised they don't because they can."

On average, business-focused firms are worth more--a median of $694.2 million vs. $499.1 million.

Because family-focused businesses operate in service to the family and are more susceptible to the influences of non-business family members, advisers say they need a form of family governance. Many, however, can't get past family issues: The patriarch is grappling with mortality and his heirs are grappling with one another.

"Dysfunction is the norm," Prince says. "Having money doesn't make you less dysfunctional. It just gives you more places to hide it."

The study found that a coach can help family-focused businesses navigate issues that have the potential to unravel their strategies, including personal lawsuits.

"People deceive themselves," Prince notes. "Success mitigates these issues. But then somebody dies and the family goes to war."

by Roberta C. Yafie