Berkshire - on Management

From Yr 2010 Results Review - http://www.berkshirehathaway.com/letters/2010ltr.pdf
Partially offsetting our anchor of size are several important advantages we have. First, we possess a cadre of truly skilled managers who have an unusual commitment to their own operations and to Berkshire.
Many of our CEOs are independently wealthy and work only because they love what they do. They are volunteers, not mercenaries. Because no one can offer them a job they would enjoy more, they can’t be lured away.
At Berkshire, managers can focus on running their businesses: They are not subjected to meetings at headquarters nor financing worries nor Wall Street harassment. They simply get a letter from me every two years (it’s reproduced on pages 104-105) and call me when they wish. And their wishes do differ: There are managers to whom I have not talked in the last year, while there is one with whom I talk almost daily. Our trust is in people rather than process. A “hire well, manage little” code suits both them and me.
Berkshire’s CEOs come in many forms. Some have MBAs; others never finished college. Some use budgets and are by-the-book types; others operate by the seat of their pants. Our team resembles a baseball squad composed of all-stars having vastly different batting styles. Changes in our line-up are seldom required.