Some folks just imagine conflicts that do not exist

It may make great theater, but terrible science.

In the latest issue (#67) of the real-world economics review, Egmont Kakarot-Handtke presumes to moderate a debate (PDF) between Paul Krugman and Steve Keen (PDF). Sadly, Kakarot-Handtke’s paper lies at that unfortunate intersection of incomprehension and irrelevance. The paper is irrelevant, in that Kakarot-Handtke imagines a debate between loanable-funds and endogenous-money approaches to macroeconomics that to my eye does not exist (at least in this context.) The paper demonstrates incomprehension in that Kakarot-Handtke attributes to the loanable-funds model a non-existent property.

To the latter, we hardly need look beyond the final words Kakarot-Handtke offers:

The structural axiomatic analysis leads to the prediction that Krugman’s loanable funds model will be clearly refuted. It simply does not happen in the actual monetary economy that saving and dissaving of the households is exactly equal.

Here, Kakarot-Handtke appears to tear down a straw man. The textbook loanable funds model is one in which households lend to businesses– directly or indirectly– for investment purposes. If the loanable funds model predicted that households neither saved nor dissaved on net, then there would also be no investment. What Kakarot-Handtke actually argues is that even in a purely consumption-based economy, that households can save or dissave on net if businesses dissave or save, respectively. Surely nothing Krugman has written can make one wonder if he disputes this point.

Nevertheless, Kakarot-Handtke manages to get there. Specifically, Kakarot-Handtke quotes Krugman (twice!) as saying

If I decide to cut back on my spending and stash the funds in a bank, which lends them out to someone else, this doesn’t have to represent a net increase in demand.

So it is disconcerting to see Kakarot-Handtke then go on to comment

From the quote above it is clear that for Krugman savers and dissavers are not independent. For someone who saves there is someone else who takes the money, courtesy of the intermediation of the banking system, and spends it. Hence there is no effect on the rest of the economy.

(emphasis again added)

Kakarot-Handtke‘s paraphrase is disconcerting for multiple reasons. First, Krugman does not argue that “there is someone else who takes the money.” Rather, he makes a conditional argument– that if someone else takes the money, then this doesn‘t have to represent a net increase in demand. Nothing Krugman wrote implied that he believes saved money must be lent, making Kakarot-Handtke‘s paper a complete non-sequitur.

Further, nothing Krugman wrote implied that he believes that lending necessitated a prior act of household saving. A single offered example need not constitute an exhaustive list of the universe of possibilities. Importantly, this suggests no obvious endorsement of pure loanable funds modeling here, as Kakarot-Handtke insists. Quite to the contrary, Krugman wrote

Keen says that it’s because once you include banks, lending increases the money supply. OK, but why does that matter?

What part of “OK” does Kakarot-Handtke fail to understand? Krugman is not arguing against endogenous money, but rather wondering aloud what the complication adds. I am inclined to wonder as well. Kakarot-Handtke‘s contrived example sheds no light on the subject, arguing only that households may save or dissave.

In fact, Krugman is sympathetic to the idea that debt plays a role in influencing aggregate demand. He writes

In the kind of model Gauti and I use, lending very much can and does increase aggregate demand, so what is the problem?

Krugman goes on to take issue with the notion that lending by definition adds directly to aggregate demand. In truth, much of the problem is that Keen simply makes up his own definition of “aggregate demand” which includes

income plus the change in debt, and that this is expended on both goods and services and purchases of financial claims on existing assets

He then produces the equation \begin{equation} Y\!\left(t\right)+\frac{d}{dt}D\!\left(t\right)=G\!D\!P\!\left(t\right)+N\!AT\!\left(t\right) \end{equation} Yet this construction is catastrophically non-specific. Consider Keen‘s Figure 3, titled “Aggregate demand as income plus change in debt.” The figure shows, however, nominal GDP plus change in debt. Is $Y$ then equal to nominal GDP? In that case, we are left with \begin{equation} \frac{d}{dt}D\!\left(t\right)=N\!AT\!\left(t\right) \end{equation} and find that the “change in debt” is spent entirely on existing assets, and does not add to aggregate demand in the usual sense at all. Clear as mud, that.