Landes on Family Businesses

Today's NY Times reviews the new book by Harvard economic historian David Landes, titled Dynasties: Fortunes and Misfortunes of the World’s Great Family Businesses. A tidbit from the review:

Landes also wants to make a larger point, which is that the business-school mythos of the “professional manager” has led to a persistent underestimation of the importance of family firms. Fully a third of Fortune 500 companies can properly be characterized as family businesses, and on average they outperform the “professionally managed” firm by a surprisingly large margin.

I wonder how this affects David's view of the estate tax.