(FORTUNE Magazine) – The greatest wealth transfer in history is supposedly under way as middle-aged baby-boomers inherit the assets amassed by their parents. How big will the booty be? Huge, to be sure, but not nearly as large as eager beneficiaries, bankers, brokers, and boat dealers imagine. The heirs and those who hope to sell them investment advice and big-ticket consumer goods have fixated on a recent estimate by Cornell University economists Robert B. Avery and Michael S. Rendall, given wide circulation in the media, that the boomers stand to inherit as much as $10.4 trillion (in 1989 dollars). But that staggering figure is yet another of those statistics more bandied about than carefully scrutinized. The economists projected forward changes in the demographics of the elderly population and their financial holdings through the year 2040. But by that distant date, even the youngest of any surviving boomer parents will be over 100 years old. Avery and Rendall's more realistic estimate of what the boomers themselves stand to inherit: some $4.8 trillion through 2015. In a touching demonstration of intergenerational generosity, nearly three- quarters of boomers surveyed by First Interstate Bank in Los Angeles said their parents should spend their money on themselves. But that's probably what a lot of them intended to do anyway.

CHART: NOT AVAILABLE CREDIT: FORTUNE CHART/SOURCE: FIRST INTERSTATE BANK CAPTION: What boomers would do with a legacy of $50,000