So Raghuram Rajan has posted a further explanation of his case for raising interest rates in the face of very high unemployment, presumably a response to Mark Thoma. It’s good to see Rajan put his cards on the table — but what he says only further confirms my sense that we’re talking about some kind of psychological desire to be tough, rather than the kind of analysis one would expect from a highly trained economist.

Rajan’s argument boils down to two assertions:

1. Raising rates a bit wouldn’t significantly deter investment.

2. “Unnaturally low” interest rates are distorting asset prices.

The first thing to say about these two assertions is that they are essentially contradictory. If the difference between current rates and the rates Rajan wants is trivial — just a wafer thin mint — how can that same difference be leading to a major distortion in financial markets? Are we to believe that an interest rate change that matters not at all to firms making real investments somehow has huge effects on speculators? And actually, don’t asset prices themselves matter for real investment?

It might be worth noting, in this context, that just because the interest rate on safe bonds is near zero, that doesn’t mean that people making risky investments can borrow at near-zero rates.

Beyond all that, what does Rajan mean by “unnaturally low” rates? What makes them unnatural?

My take on the current economic situation is quite simple, and I would have thought corresponds to standard economics. Right now, we clearly don’t have enough demand to make full use of the economy’s productive capacity. This means that the real interest rate is too high. And so the “natural” thing is for the real rate to fall. Yes, that would mean a negative real rate. So?

The trouble is that getting that negative real rate isn’t easy, because the nominal rate can’t go below zero, and there’s no easy way to create expected inflation. If you ask what would happen if prices were completely flexible, the answer, as I figured out long ago, is that prices would fall so far now that people would expect them to rise in the future, creating expected inflation. Bur prices aren’t that flexible, which is why we turn to quantitative easing, fiscal policy, and more.

Surely, though, we want to get rates as close to their appropriate level as possible — which means a zero nominal rate. There’s nothing “unnatural” about it. On the contrary, the “natural rate of interest”, as Wicksell defined it, is clearly negative right now.

So why does Rajan feel that there must be something wrong with low rates (and he’s not alone)? I think his language, with its odd moral tone, is the giveaway: it’s the sense that economic policy is supposed to involve being tough on people, not giving money away cheap.

I actually understand the seductiveness of that posture; I can sort of understand how economists succumb to it. But right now, with the world desperately in need of clear thinking, is no time to give in to the subtle allure of inflicting economic pain.