If not, perhaps you've seen the British Airways ads offering "101 Ways to Spend the Kids' Inheritance." An article in that issue takes us a big step closer to answering the most common question readers ask: "How much can I spend each year and not run out of money?" The article's title isn't as catchy as "How to Spend the Kids' Inheritance." If you retire at age 60 and are fortunate enough to have accumulated $1 million, the current conventional wisdom says you can spend about $40,000 a year, adjusted for inflation each year, for 30 years. Combine the probabilities of death with the probabilities of portfolio returns, and you can start spending at $50,338 a year. Having to assume an investment period of 30 years, from 65 to 95 or from 70 to 100, made leaving money on the table almost inevitable. A study by the Center for Retirement Research at Boston College, in fact, found RMDs were a more efficient tool than Bengen's 4 percent rule. Remember, there is a five-year life expectancy difference between the top and bottom of the U.S.