While the Republican candidates are obsessing over the national debt, economists are thinking the opposite, that Keynesianism is back and a lot of borrowing and spending is going to be necessary to keep the economy going. Your average person on the street can follow the first argument, because it seems similar to his household finances, and because it has an undertone of morality (debt=bad). But very few people understand the theories behind fiscal or monetary policy. Because our education system hasn’t given us the mental tools to understand the nested complex systems we are all embedded in. How are we supposed to elect the right people to make the right choices then?

Finally, there is a fourth view, championed most prominently by Larry Summers and Paul Krugman. They argue that there is little evidence that monetary policy will ever restore full prosperity. In this view, Milton Friedman’s dream of using strategic monetary interventions to offset economic shocks remains just that: a dream. It was only the unique circumstance in Europe and the US over the last half-century – most notably rapid demographic and productivity growth – that made his ideas seem plausible. “If nobody believes that inflation will rise, it won’t,” is how Krugman put it. “The only way to be at all sure of raising inflation is to accompany a changed monetary regime with a burst of fiscal stimulus.”

I do not claim to know which of these views is the correct one. But I do think that this discussion is the most important debate in the field of macroeconomics since John Maynard Keynes wrestled with similar questions in the 1930s. For Keynes, the answer was clear, and it was something close to what is being argued by Summers and Krugman; indeed, his conclusions are what transformed him from a monetarist into a Keynesian.

“It seems unlikely that the influence of [monetary] policy on the rate of interest will be sufficient by itself,” Keynes wrote in 1936. “I conceive, therefore, that a somewhat comprehensive socialization of investment will prove the only means of securing an approximation to full employment.” Those are words worth considering the next time we find ourselves needing the courage to act.

Oh, even if monetary policy did work, the Republicans want to destroy the Federal Reserve.