There is a lower zone in which a shortage of money begins to present
diflScuIties both for private investment and fiscal policy, and there is
an upper zone in which an excess of money begins to become apparent.
The range between these lower and upper levels of the money supply
is, however, rather wide in advanced and wealthy industrial countries
such as the United States; in contrast, this range is comparatively
narrow in the primary producing and relatively underdeveloped
countries.