I’ll make this short because I’ve covered this ground in this blog before, but recent gains in GBP in response to the latest inflation data and the more hawkish tone from the Bank of England at the September meeting make it worthwhile to go over it once again.
First, the basics. Higher inflation, other things equal, should mean a currency goes down, not up, in order to maintain the relative price level. The fact that currencies tend to rise in the short run with upside surprises in inflation is an anomaly seemingly based on a combination of money illusion and a historic expectation that higher inflation will trigger a response from the central bank that will actually mean higher real interest rates. This seems to be a distant memory of the 1970s and 80s, because it is hard to find occasions in the more recent past where higher inflation has triggered higher real rates (as opposed to just higher nominal rates) in the major economies. Of course, real rates have been falling steadily for years as a result of structural as opposed to cyclical factors, but even the cyclical upturns have seen precious little rise in real rates (see the FX market needs to rethink inflation, November 18 2016).
All this is relevant to the recent reaction to UK news. Inflation is above target and still rising, mainly in response to the decline in GBP seen after the Brexit vote. The MPC is now considering a rate rise in response. But the rate rise will come nowhere near full compensation for the rise in inflation seen since the Brexit vote. Real rates have fallen, and even if we see a 0.25% rise in the base rate soon they will still be well below where they were not just before the Brexit vote, but immediately after the BoE cut in rates after the vote (see chart below). While inflation has also risen elsewhere, it has not moved as much, and UK real rates remain unattractive, and will remain unattractive even if they move modestly higher.
Real UK base rate
Source: Bank of England
On top of this, there is the question of whether higher real rates in these circumstances, if they were to come, should be seen as positive for GBP. In general, higher real rates are theoretically positive for a currency, but in the current UK situation Carney’s speech yesterday makes it clear that his case for higher rates is based primarily on the expected inflationary consequences of Brexit. This is not the usual cyclical impact of rising demand, but a structural change that will reduce both demand and supply and raise prices, at least in the short run, with Brexit effectively acting as a de-globalisation. Carney’s case for higher real rates essentially rests on the belief that the Brexit impact on supply will be greater than the impact on demand. This is debatable (as he himself admits) and it is hard to instinctively see this as positive for GBP, because real rates will be rising because of reduced potential output due to reduced efficiency and lower productivity. Any benefit from higher portfolio inflows to seek out the higher real rates seems likely to be offset by reduced inward direct investment as a result.
In summary, the case for GBP gains based on a more hawkish BoE seems very weak. Any rise in nominal rates looks unlikely to translate into a rise in real rates, and to the extent that real rates are higher than they would have been, it will likely only reflect the Bank’s concern that Brexit is going to undermine potential UK output growth by reducing productivity and undermining existing supply chains. Of course, that doesn’t mean GBP will reverse recent gains quickly (the market can remain irrational longer than you can remain solvent), but looking at the charts suggests to me that 1.38 would be a very good area to sell GBP/USD, while anything below 0.87 looks a buying area for EUR/GBP.