Not very often, but occasionally he hit on something of importance.
For example, he said in the Communist Manifesto that: “The cheap prices of its commodities are the heavy artillery with which [ the profit system]…compels all nations, on pain of extinction, to adopt the [ profit]… mode of production.” President Obama evidently missed that passage, since he claimed in a debate with Mitt Romney that the government could provide health services more cheaply because it did not have to earn a profit. The truth, as even Marx understood, is that the search for profit drives prices down.
One of the few things Keynes got right was his dismissal of Marx. He told his student Michael Straight: ” Marxism was even lower than social credit as an economic concept. It was complicated hocus-pocus.” [ Skidelsky, vol 2, p 523] Curiously, Marx had already said much the same about Keynesianism, even before Keynes was born. His scorn for Keynesianism was of course possible because there wasn’t anything particularly new about what Keynes said.
Here is the passage from Capital [ P. 827-29] in which Marx seems to be anticipating the Keynesian system:
“The only part of the so-called national wealth that actually enters into the collective possessions of modern people is– their national debt. Hence,…the modern doctrine that a nation becomes richer the more deeply it is in debt. Public debt becomes the credo of capital. And with the rise of national debt-making, want of faith in the national debt takes the place of blasphemy against the Holy Ghost….
As with the stroke of the enchanter’s wand…, [ the public debt] endows barren money with the power of breeding and thus turns it into capital.”… [But] modern fiscal policy…contains within itself the germ of automatic progression. Overtaxation is not an accident, but rather a principle.”
It would be fitting punishment for Marx and Keynes to have to debate each other face to face forever in some gloomy spot beyond the River Styx.