stall. Then Bruce asked a momentous question: 'What about business strategy?' I objected: 'That's too vague. Most executives won't know what we're talking about.' Bruce replied, 'That's the beauty of it. We'll define it'.—Robert E. Mainer, Boston 1964-1967 Bruce created the publication entitled Perspectives as a new form of marketing and in response to the McKinsey Quarterly and Arthur D. Little's Prism. He wrote extensively for the publication until 1980. In 1974 Henderson made BCG an independent business and was one of the first to take advantage of the Employee Retirement Income Security Act of 1974 that allowed the establishment of an employee stock ownership plan (ESOP). The ESOP began the process of buying BCG from The Boston Company, the parent corporation of Boston Safe Deposit. The buyout was completed in 1979, five years ahead of schedule. Between 1974 and 1980, Henderson focused on growing the firm and expanding its international presence. By the end of 1977, revenues were split evenly among business originating in the United States and overseas. Retirement Henderson stepped down from his role as the president and CEO of Boston Consulting Group in 1980. He was succeeded by Alan Zakon. By that time, he had grown BCG from a one-man-shop to a global firm with seven offices and 249 consultants. He continued as the chairman until 1985. He retired and went to Nashville, Tennessee, to teach at the Owen Graduate School of Management at Vanderbilt University. Death Henderson died at the age of 77, ten days after suffering a heart stroke at his home in Nashville in 1992. He was survived by his second wife, four children with his first wife, and seven grandchildren. A memorial service was held with an overflow of attendees at the Memorial Church at Harvard Yard, Cambridge, on December 11, 1992, amidst a blizzard. Speakers at the service included John S. Clarkson, then-president and chief executive officer of BCG, George Stalk, a senior vice president of BCG, and Alan Zakon, former BCG chairman. Ideas and concepts The experience curve "The strategic implications of the experience curve came closer to shattering earth."—The Economist, 2009 The Experience Curve is a managerial tool primarily used to predict cost behaviour. It states that "costs characteristically decline by 20-30% in real terms each time accumulated experience doubles. This means that when inflation is factored out, costs should always decline. The decline is fast if growth is