Where did the idea behind FIRECalc come from?
In 1997, Trinity University professors Philip Cooley, Carl Hubbard, and Daniel Walz published a study entitled The Trinity Study: Annual Withdrawal Rates and Portfolio Success. While other studies had looked at long term survival of various specific investments, this study was the first widely disseminated research showing that retirees whose annual spending was more than around 4% of their starting portfolio would outlive their nest eggs, regardless of how they invested. John Greaney, who hosts the Retire Early Home Page website created a spreadsheet to illustrate these effects. His site and spreadsheet, and an associated forum he hosted at The Motley Fool’s website, brought the concept to a lot of people who had not considered it before, including FIRECalc’s author. That spreadsheet was the inspiration and model for the original FIRECalc, which was developed to add the ability to schedule changes to future withdrawals (such as might be made when the retiree becomes eligible for Socia
