/biz/ - Business & Finance

Think in terms of opportunity cost. Think of every dollar you spend as the amount it could grow into by the time you retire. Ben Franklin famously advised, “A penny saved is a penny earned.” He was right but not entirely right. The Rule of 72 shows why. If you save money and invest it at, say, a 7 percent average annual return, $1 saved today becomes $2 in about 10 years, $4 in 20 years, and $8 in 30 years, and so on and on, inevitably growing. So the dollar a young person spends on some nonessential today would mean that $10 or more will be given up in retirement.