Rating the online RETIREMENT planners.

The article focuses on the tools used in retirement planning. The author says a software can calculate probabilities based on a long list of assumptions, including the rate of inflation and investment returns. A Monte Carlo simulation can factor in a range of possible returns as well as a range of inflation rates and other factors. Morningstar's Asset Allocator assumes retirees will be conservative so it builds in a gloomy 1%-a-year after-inflation return on investments after retirement.