Since the war the economies of some developed countries appear to have been growing exceptionally fast (table 1, chart 1). From 1950 onwards six countries have shown growth rates of 3 to 6 per cent; four of these have shown rates of over 3 per cent since 1954, by which time the effects of post-war recovery might be expected to have been over. These rates are nearly all more than twice as high as the long-term averages of the countries concerned. Does this imply that they are some kind of spurt rates which will inevitably revert, sooner or later, to more ‘normal’ rates of growth?