In pre-war days, when almost the whole world was on a gold standard, we had all plumped for stability of exchange as against stability of prices, and we were ready to submit to the social consequences of a change of price level for causes quite outside our control, connected, for example, with the discovery of new gold mines in foreign countries or a change of banking policy abroad. But we submitted, partly because we did not dare trust ourselves to a less automatic (though more reasoned) policy, and partly because the price fluctuations experienced were in fact moderate. Nevertheless, there were powerful advocates of the other choice. In particular, the proposals of Professor Irving Fisher for a Compensated Dollar, amounted, unless all countries adopted the same plan, to putting into practice a preference for stability of internal price level over stability of external exchange. The right choice is not necessarily the same for all countries. It must partly depend on the relative importance of foreign trade in the economic life of the country. Nevertheless, there does seem to be in almost every case a presumption in favour of the stability of prices, if only it can be achieved. Stability of exchange is in the nature of a convenience which adds to the efficiency and prosperity of those who are engaged in foreign trade. Stability of prices, on the other hand, is profoundly important for the avoidance of the various evils described in Chapter I. Contracts and business expectations, which presume a stable exchange, must be far fewer, even in a trading country such as England, than those which presume a stable level of internal prices. The main argument to the contrary seems to be that exchange stability is an easier aim to attain, since it only requires that the same standard of value should be adopted at home and abroad; whereas an internal standard, so regulated as to maintain stability in an index number of prices, is a difficult scientific innovation, never yet put into practice.