A canary in the coalmine?

A couple of days ago, I put this chart and brief comment on Twitter

I added “I do not think nom GDP targeting is generally superior to inflation targeting for NZ, but recent outcomes (latest annual 5.9%) are at least one reason for a little caution about further aggressive OCR increases”.

There is a long history of people writing about nominal GDP targeting (it was being championed in some of the literature before inflation targeting was even a thing). I’ve written about it a few times (including here and here) and just this morning I noticed a new commentary from Don Kohn, former vice-chair of the Federal Reserve looking (sceptically) at some of the issues. No central bank has shifted to nominal GDP targeting (whether in levels or growth rates) but a fair number of people (including Kohn) will suggest that there may still be useful information in developments in nominal GDP – something to keep at least one eye on.

Almost every piece of economic data has been made harder to interpret over the last couple of years by Covid. In my chart, the eye immediately tends to go to the unprecedented fall (in 2020) and unprecedented rebound following that. But my eye next went to what wasn’t there: the most recent rate of increase (nominal GDP in the June 2022 quarter is estimated to have been 5.9 per cent higher than that in the June 2021 quarter) wasn’t at all out of line with typical experience in the last few decades. It is quite a different picture than we see with headline and core inflation measures. And although Covid has continued to affect economic numbers, last June quarter seemed relatively little affected by Covid here (the Delta outbreak was mid-August), and by the June quarter we were through the worst of the restrictions. Perhaps as importantly for what follows, the June quarter was pretty normal for most other countries too (and the June 2020 quarter was pre-Omicron disruptions).

One upside of New Zealand’s slow publication of macroeconomic data is that when our GDP numbers are finally published, pretty much everyone else’s are available for comparison. And although people often note (fairly) that nominal GDP numbers are published with a longer lag than inflation numbers, we are also now in the long New Zealand hiatus where it is two months since we last saw an inflation number, and another month until we get another one. The MPC makes its next OCR decision before that.

So how did New Zealand’s estimated nominal GDP growth for the year from the June quarter last year to the June quarter compare with the experience of other OECD economies? Here I’m focused on places having their own monetary policies, and so show the euro-area rather than the individual countries in that area. I’m also going to leave Turkey off my charts – mostly to keep them more readable, in a context where they are running a crazy monetary experiment and have recorded nominal GDP growth of 115 per cent in the last year.

Nominal GDP growth in (fairly low inflation) Norway went sky-high because the invasion of Ukraine etc has sent oil and (especially) gas prices very high.

But look at New Zealand: we had the fourth lowest rate of nominal GDP growth in that year among all the OECD countries (monetary areas). And two of those below us – Switzerland and Japan – had not only not eased monetary policy in 2020, but had spent years grappling with such low inflation they’d needed persistently negative policy interest rates.

Absolute comparisons like this can mislead a bit. Some countries have higher inflation targets than others – Chile, Costa Rica, Mexico, and Colombia for example target 3 per cent inflation, and have historically had somewhat higher nominal GDP growth rates consistent with those higher targets. But I could take the Latin American countries (poor enough that they are really OECD diversity hires) off the chart and it wouldn’t much change the picture as it affects New Zealand and the countries we often compare ourselves to. In Australia, for example, nominal GDP increased by almost 12 per cent in the year to June.

The last quarter before Covid was December 2019. Across the OECD as a whole (and in New Zealand) core inflation at the time was generally a bit under the respective (core) inflation targets, and many central banks had been cutting policy rates that year.

Here is nominal GDP growth (as now recorded – GDP revisions are a thing) for the same group of countries for the last pre-Covid year.

New Zealand’s rate of nominal GDP growth then was a bit higher than the median OECD country, perhaps consistent with the fact that our population growth rate was faster than those for most advanced countries. But our nominal GDP growth rate that year was also a bit higher than the average rate New Zealand had experienced in the previous decade or more. (Note Norway again; not even the staunchest advocates of nominal GDP targeting recommend it for countries with terms of trade shocks on that scale.)

The next chart shows annual growth in nominal GDP for the latest period less annual growth to the end of 2019. The idea is to see how much acceleration there has been (with the sort of lift in core inflation we’ve seen across most of the world all else equal one might expect to have seen quite a lift in nominal GDP growth).

Fair to say that New Zealand stands out somewhat. In the year to June 2022 New Zealand was the only OECD country to have had nominal GDP growth lower than in the immediate pre-Covid period. And if our terms of trade have fallen a bit in the last year, that was still in a context where (NZD) export prices were up 17 per cent in the most recent year, with import prices up even more.

I am genuinely not sure what to make of these pictures and the New Zealand comparisons specifically. If you look across that last chart you would have little hesitation in suggesting that a lot of monetary policy tightening (interest rate rises) has been warranted in the advanced economy world. For the median country, nominal GDP growth has accelerated by 6 percentage points. But in New Zealand, nominal GDP growth has slowed.

And if one were a champion of nominal GDP levels targeting, here is New Zealand’s nominal GDP over the last decade

Things have (inevitably) been bumpier in the Covid period, but there is nothing there suggesting things have gone off track in recent times (although the mix has changed, with less population growth and more inflation).

The usual fallback position when anyone invokes nominal GDP numbers is to note (entirely fairly) that revisions to GDP are very much to be expected. Perhaps we will find, five years hence, that nominal GDP growth in the year to June 2022 was really a couple of percentage points higher than SNZ currently estimate. That would be a pretty large change for a single year (as distinct from historical levels revisions as data collections and methodologies change). But – if every other country’s estimates didn’t change – one could revise up New Zealand’s rate of nominal GDP growth by 2 percentage points and we would still be equal lowest (with Japan – where they are still running avowedly expansionary monetary policy) on that chart showing the acceleration in the rate of nominal GDP growth.

Two other considerations are worth noting. It isn’t true that our Reserve Bank was particularly early in raising the OCR again – about six of these countries were ahead of them – but market interest rates had already risen quite a bit last year in anticipation and we had had one of the frothiest housing market during the Covid period, and are now somewhat ahead of the pack in seeing house prices and house turnover falling away. Even if – as I am – one is sceptical of house price wealth effects, housing turnover itself is one (modest) component of GDP. Either way, our subdued nominal GDP growth may be foreshadowing what could be about to happen elsewhere.

Monetary policy is avowedly run on forecasts – that would be true (or the rhetoric) even if one were targeting nominal GDP growth rather than inflation – and I guess it is always possible that we might see an acceleration of nominal GDP growth from here, that might support further Reserve Bank tightening from here. Perhaps, but it is difficult to see quite where this acceleration might come from.

I have been a little more sceptical than some in recent months of quite how much further the OCR is really likely to need to be raised, but I am not drawing strong policy conclusions from these data just yet. But they do seem like a straw in the wind that (a) warrants further investigation and (b) might make one somewhat cautious about championing further tightenings, especially in the absence of timely fresh inflation data. Subdued growth in nominal GDP is more or less exactly what one might expect to see if, with a lag, core inflation was already on track to slow, perhaps quite a bit.