Irving Fisher,
The Purchasing Power of Money…
“ If trade unions seek to raise prices of labor while trusts raise prices of commodities, the general level of everything may rise or fall; but it can rise only by a general decrease in the quantities of commodities, labor, etc., sold, or by an increase of currency, or by an increase in velocities of circulation. If there is neither an increase nor decrease in volume of business, and if the quantity and velocity of circulation of money and its substitutes remain unchanged, the price level cannot change. ”
