With the Social Security system entering a financial abyss, it’s time for a replacement, says Boston University economics professor Laurence Kotlikoff.

“We need a new system, which retains Social Security’s best features, scraps the rest, and covers its costs,” he writes in a Bloomberg column

“Social Security’s objective — forcing people to save for retirement — is legit. But Social Security has also played a central role in the massive, six-decade Ponzi scheme known as U.S. fiscal policy, which transfers ever-larger sums from the young to the old.”

The basic problem is that as baby boomers retire, they and their elders will take more money out of the system than is going in.

Social Security itself is broke and has a $16 trillion gap between future spending and revenue, he says.

Kotlikoff recommends a new system in which workers contribute 8 percent of their pay. Contributions would be invested by the government in an index of stocks, bonds, and real estate. Balances would be swapped for inflation-indexed annuities between ages 57 and 67.

“(That) meets all the legitimate goals of Social Security without the system’s waste and penchant for robbing the young,” Kotlikoff writes.