One immediate effect of the oil price plunge is to turn the stock markets' star pupils, the oil majors, into dunces. Some $51bn has been knocked off the share prices of Europe's big three companies BP, Shell and Total Fina in the last 48 hours. If the IMF is correct in its diagnosis and two of the world's biggest oil importers, the US and Japan, remain mired in slump through most of next year, there is no reason to expect any real bounce in energy prices.