About 30% of family business owners who expect to retire in 5 years have no estate plans other than wills.

Researchers at Massachusetts Mutual Life Insurance Company, Springfield, Mass., and Kennesaw State University are reporting that finding in a summary of results from a survey of more than 1,000 family-owned businesses.

About three-quarters said revenue has grown over the past 3 years, and more than 33% said revenue has grown more than 11%, the researchers report.

But the percentage of owners who expect to retire soon and have no estate plan other than a will has doubled since 2002, the researchers report.

In addition, fewer than half of the owners who plan to retire in the next 5 years have chosen successors.

About a third of the firms surveyed said the successor to the owner might be a woman.