The cost-of-living crisis is international, with few countries escaping its impact. When UK consumer price inflation hit 7% in March (though 9% when measured by the old retail prices index) inflation in the eurozone was 7.5% and in America at a 40-year high of 8.5%.

Some countries have done more to limit the impact of rising energy prices. France, taking advantage of the fact that the electricity giant EDF is 84% state-owned, limited the rise in energy bills this year to 4%, and is committed to reducing petrol and diesel prices by 15 cents a litre, equivalent to 12 pence, compared with Rishi Sunak’s 5p a litre reduction, not all of which was passed on to customers. French inflation has thus been running below competitor countries and was 5.1% in March.

Past experience with price controls would suggest, however, that they can only offer temporary relief. If inflation is to come out it will do so. A similar argument applies to the windfall tax on energy firms proposed by Britain’s Labour Party. Only if high inflation is expected to be temporary can one-off measures like this work.

Forecasters, having been caught out by the surge in inflation, do mainly expect it to be short-lived. The Office for Budget Responsibility (OBR), in its latest forecast, published on March 23, predicted that inflation will have two peaks this year. One peak, this spring, will be almost 8%. The second, later in the year, will be a touch below 9%. Other forecasters think that the second peak could see inflation in double figures, if only temporarily.

The OBR then predicts that inflation will then head lower quite dramatically, to under 4% in the spring of next year and below 2% by the end of 2023. The mechanism for this is not, in the main, falling prices but that energy prices will level off after this year, thus no longer driving inflation higher.

When faced with a forecast like this, which on the face of it looks almost too good to be true, that acerbic quote from J K Galbraith springs to mind, that economic forecasters were put on this earth to make astrologers looks respectable. The future course of inflation depends on many variables, not least whether it becomes “embedded” via second-round effects, including rapidly rising wages.

There is no evidence of that yet, which means that the inflation outlook is, in a throwback to past inflationary episodes, acutely sensitive to energy and commodity prices. The National Institute of Economic and Social Research (NIESR), one of the oldest economic think tanks, recently looked at different inflation scenarios, some directly linked to the Russian invasion of Ukraine.

Russia-Ukraine has created an energy price shock, on top of existing inflationary pressures. It has also created a commodity shock with, as NIESR noted, a significant impact on the supply of wheat and other grains; fertilizer, where Russia accounts for 20% of world supplies and of the ingredients to make it, notably ammonia, urea and potash; neon, with 50% of semiconductor grade neon coming from two Ukrainian companies, and metals, with Russia a main supplier of nickel, gold, palladium, copper and aluminium.

Of the inflation scenarios sketched out by NIESR, two stand out. One, which it calls its “medium” scenario, is in which inflation settles down from now on at a rate consistent with the official 2% target, in other words with prices rising by 0.17% a month. It takes time, even under this scenario, to get back to that 2% target, but, as with the OBR, the rate is back to 4% by next spring.

Much less comfortable is the think tank’s “sanctions” scenario, in which the impact of sanctions on Russia is to limit energy and commodity supplies and inflation averages what NIESR says could be a conservative estimate of 0.6% a month, equivalent to around 7% a year. Under this scenario, inflation reaches 9.8% next January “and is likely to remain there for some time”. That, it should be said, is not part of anybody’s plan, in business, government or the financial markets. But it would be foolish to deny that it could happen. For reference, the monthly rise in the consumer prices index from November to March averaged 0.6%.

It is a useful way of looking at it, and a reminder that in a world of surprises very little is certain at present, including the inflation outlook. We can hope for the best, but we cannot deny the possibility of the worst.