Bill Bengen, the retirement researcher who created the well-known 4% rule, has a message for early retirees: you might be living more frugally than necessary. "I think they're cheating themselves a little bit," Bengen told CNBC’s Make It about retirees who rigidly follow his original guidance (1). The issue isn't that Bengen's research was wrong. Rather, he argues that many retirees focus on static percentage — 4%, or his updated 4.7% — without considering the economic and market conditions that determi ...