Mercantilism in its simplest form is bullionism, yet mercantilist writers emphasize the circulation of money and reject hoarding. Their emphasis on monetary metals accords with current ideas regarding the money supply, such as the stimulative effect of a growing money-supply. Fiat money and floating exchange rates have since rendered specie concerns irrelevant. In time, industrial policy supplanted the heavy emphasis on money, accompanied by a shift in focus from the capacity to carry on wars to promoting general prosperity. Mature neomercantilist theory recommends selective high tariffs for "infant" industries or the promotion of the mutual growth of countries through national industrial specialization.