Cachanosky on the productivity norm, Hayek’s rule and NGDP targeting

Nicolas Cachanosky and I should get married (intellectually, don’t get overexcited). Some time ago, I wrote about his very interesting paper attempting to start the integration of finance and Austrian capital theories. A couple of weeks ago, I discovered another of his papers, published a year ago, but which I had completely missed (coincidentally, Ben Southwood also discovered that paper at the exact same time).

Titled Hayek’s Rule, NGDP Targeting, and the Productivity Norm: Theory and Application, this paper is an excellent summary of the policies named above and the theories underpinning them. It includes both theoretical and practical challenges to some of those theories. Cachanosky’s paper reflects pretty much exactly my views and deserved to be quoted at length.

Cachanosky defines the productivity norm as “the idea that the price level should be allowed to adjust inversely to changes in productivity. […] In other words, money supply should react to changes in money demand, not to changes in production efficiency.” Referring to the equation of exchange, he adds that “because a change in productivity is not in itself a sign of monetary disequilibrium, an increase in money supply to offset a fall in P moves the money market outside equilibrium and puts into motion an unnecessary and costly process of readjustment”, which is what current central bank policies of price level targeting do. The productivity norm allows mild secular deflation by not reacting to positive ‘real’ shocks.

He goes on to illustrate in what ways Hayek’s rule and NGDP targeting resemble and differ from the productivity norm:

There are instances where the productivity norm illuminated economists that talked about monetary policy. Two important instances are Hayek during his debate with Keynes on the Great Depression and the market monetarists in the context of the Great Recession. Both, Hayek and market monetarism are concerned with a policy that would keep monetary equilibrium and therefore macroeconomic stability. Hayek’s Rule and NGDP Targeting are the denominations that describe Hayek’s and market monetarism position respectively. Taking the presence of a central bank as a given, Hayek argues that a neutral monetary policy is one that keeps constant nominal income (MV) stable. Sumner argues instead that

“NGDP level targeting (along 5 percent trend growth rate) in the United States prior to 2008 would similarly have helped reduce the severity of the Great Recession.”

Hayek’s Rule of constant nominal income can be understood in total values or as per factor of production. In the former, Hayek’s Rule is a notable case of the productivity norm in which the quantity of factors of production is assumed to be constant. In the latter case, Hayek’s rule becomes the productivity norm. However, for NGDP Targeting to be interpreted as an application that does not deviate from the productivity norm, it should be understood as a target of total NGDP, with an assumption of a 5% increase in the factors of production. In terms of per factor of production, however, NGDP Targeting implies a deviation of 5% from equilibrium in the money market.

Cachanosky then highlights his main criticisms of NGDP targeting as a form of nominal income control, that is the distinction between NGDP as an ‘emergent order’ and NGDP as a ‘designed outcome’. He says that targeting NGDP itself rather than considering NGDP as an outcome of the market can affect the allocation of resources within the NGDP: “the injection point of an increase in money supply defines, at least in the short-run, the effects on relative prices and, as such, the inefficient reallocation of factors of production.” In short, he is referring to the so-called Cantillon effect, in which Scott Sumner does not believe. I am still wondering whether or not this effect could be sterilized (in a closed economy) simply by growing the money supply through injections of equal sums of money directly into everyone’s bank accounts.

To Cachanosky (and Salter), “NGDP level matters, but its composition matters as well.” He believes that targeting an NGDP growth level by itself confuses causes and effects: “that a sound and healthy economy yields a stable NGDP does not mean that to produce a stable NGDP necessary yields a sound and healthy economy.” He points out that the housing bubble is a signal of capital misallocation despite the fact that NGDP growth was pretty stable in pre-crisis years.

I evidently fully agree with him, and my own RWA-based ABCT also points to lending misallocation that would also occur and trigger a crisis despite aggregate lending growth remaining stable or ‘on track’ (whatever that means). I should also add that it is unclear what level of NGDP growth the central bank should target. See the following chart. I can identify many different NGDP growth ‘trends’ since the 1940s, including at least two during the ‘great moderation’. Fluctuations in the trend rate of US NGDP growth can reach several percentage points. What happens if the ‘natural’ NGDP growth changes in the matter of months whereas the central bank continues to target the previous ‘natural’ growth rate? Market monetarists could argue that the differential would remain small, leading to only minor distortions. Possibly, but I am not fully convinced. I also have other objections to NGDP level targeting (related to banking and transmission mechanism), but this post isn’t the right one to elaborate on this (don’t forget that I view NGDP targeting as a better monetary policy than inflation targeting but a ‘less ideal’ alternative to free banking or the productivity norm).

Cachanosky also points out that NGDP targeting policies using total output (Py in the equation of exchange) and total transactions (PT) do not lead to the same result. According to him “the housing bubble before 2008 crisis is an exemplary symptom os this problem, where PT increases faster than Py.”

Finally, he reminds us that a 100%-reserve banking system would suffer from an inelastic money supply that could not adequately accommodate changes in the demand for money, leading to monetary equilibrium issues.

I can’t reproduce the whole paper here, but it is full of very interesting (though quite technical) details and I strongly encourage you to take a look.