The Federal Reserve has just begun to implement its third round of quantitative easing (QE3), yet some economists already are taking about the possibility of QE4.

The Fed shouldn’t go down that road, says CNNMoney’s Paul La Monica.

“Sure, Fed Chairman Ben Bernanke has continued to preach the tried-and-true central bank gospel about all this stimulus, namely that low rates won't lead to runaway inflation,” he writes.

Editor's Note: Economist Warns: ‘Money From Heaven a Path to Hell.’ See Evidence.

“But hopefully, even Bernanke, whom we should perhaps call a deflation hawk instead of inflation dove, has to realize that the Fed can't justify another round of money-dropping this soon.”

Lower interest rates aren’t the answer, La Monica says. The 10-year Treasury yield already has dropped to 1.6 percent from 3.74 percent before the financial crisis began in September 2008.

“[T]he lack of cheap financing for loans is not the biggest problem facing the U.S. economy,” he writes.

La Monica quotes Kate Warne, chief investment strategist at Edward Jones, who says that while the economy obviously is weaker than anyone would like, “the Fed has done what it can, and there is not much more that it can do."

Societe Generale strategist Dylan Grice is even more critical of the Fed — and other central banks — than La Monica is.

"All I see is more of the same — more money debasement, more unintended consequences and more social disorder,” he writes in a report obtained by Business Insider.

Editor's Note: Economist Warns: ‘Money From Heaven a Path to Hell.’ See Evidence.