UK Productivity and Demand
There’s been some discussion of UK productivity recently, Simon Wren-Lewis here, Martin Wolf here, and Scott Sumner indirectly too. What I find interesting is that UK productivity exhibits such a strong positive correlation with nominal demand growth. I’ve graphed here the growth rates of nominal GVA, and market sector output per hour.
Why do we see that procyclical movement of productivity? I’ll offer three views:
1. Firstly, this is simply what we should expect to see under an inflation-targeting central bank. The inflation-targeting CB is trying to control the gap between (growth of) aggregate demand and aggregate supply. When we have a negative productivity shock (2008, 2012) the CB must drive down nominal demand growth to prevent high inflation. That’s all this data shows; Mervyn King and the supply-side pessimists will settle for something like this view. There is no AD problem per se, it’s supply, supply, supply.
That story is muddied only a little by the difference between CPI inflation (the actual BoE target) and output price/GVA inflation. GVA inflation, averaging 1.8% over the last four years, has been stabilised by the BoE arguably more effectively than the headline CPI.
2. Another view is that the GDP data is wrong, at least post-2009. The 2012 productivity collapse is genuinely weird. The fall in market sector output/hour masks the fact that hours worked soared upward, up 2.6% over the four quarters to 2012 Q4, while market sector output contracted by -0.3% over the same period. (The GDP data still show a market sector “double-dip” in 2012, offset by the positive contribution from the
savage fiscal austerity rise in the volume measure of government consumption). There are a few theories here:
a) The idea that the GDP data is wrong is neatly supported by work on measuring intangible investment (see Goodridge, Haskel et al). I find this quite compelling because it matches an anecdotal view of what is happening in some sectors, e.g. retail. With the shift towards on-line shopping; that sector is investing in intangible assets (web sites, software etc), and there is less demand for new tangible capital (shops).
b) Markit’s Chris Williamson made the argument recently that the official labour market data which is wrong. The ONS disagreed, needless to say. Given that the change in unemployment has roughly tracked the movement in the claimant count, I’m not sure how much weight to put on this idea.
c) The nominal GDP data is right, but the inflation data, and hence output and output/hour, is wrong. A pet theory of this inflation-sceptic blogger. Under five years of 1920s-style NGDP growth we have seen widespread discounting and substitution. For the latter, think about the success of UK budget hotels, airlines, and supermarkets; this is substitution between goods/services of different quality. I strongly suspect such changes are near-impossible for the ONS to capture “correctly” in the price indices, and hence measured inflation is far too high. This makes measured productivity appear to be more procyclical than it should be if we “correctly” measured inflation and output.
3) A third view… it’s demand, demand, demand. The slow growth of NGDP was simply a mistake, it was bad macro policy. Labour hoarding and hand-waving are used to explain away the productivity data. The correlation in the graph really is a causal relation, but it goes from demand to productivity; we’ll see a recovery in productivity with a recovery in AD. So jump to it Mr. Carney/Mr. Osborne.
In optimistic moments I can subscribe mostly to (3), and 2013’s apparent recovery in output along with a recovery in demand supports that argument, in my view. Martin Wolf argues the Bank can “correct… highly visible errors” on inflation later on, after “gambling on growth”. But what is a “highly visible error” if not the last five years of UK inflation?
Supply-side optimists cannot sit on the fence and pretend the 2008-201X CPI trainwreck never happened. It’s surely more convincing to argue we should take productivity – and inflation – out of macro policy altogether. Set a stable path for nominal incomes and let the supply-side puzzle itself out.