We’ve seen this movie before.

There is widespread frustration with the performance of the economy. Traditional policy approaches are not delivering hoped-for results. A relatively unpopular president is loathed to an unusual extent by a frustrated opposition party that lost the previous presidential election while running a pillar of its establishment. And altered economic conditions have led to the development of new economic ideas that reflect a significant break with previous orthodoxy.

And now, these new ideas are being oversimplified and exaggerated by fringe economists who hold them out as offering the proverbial free lunch: the ability of the government to spend more without imposing any burden on anyone.

...

Supply-side economics was an unreasonable extension of valid ideas; few today advocate the top corporate tax rate of 46 percent and rates above 50 percent for a substantial swath of taxpayers that prevailed in the late 1970s. So, too, in a new era when the Fed chairman thinks that neutral real interest rates are well below 1?percent, we can approach federal borrowing with much less trepidation than we have traditionally.

But for neither the right nor the left is there any such thing as a free lunch. It’s the responsibility of serious economists, whatever their political party, to make this clear.