Carl Menger's different concepts of the value of money : the enigma of "the inner value of money"

In his article “Geld” of 1909 Menger introduces a principal distinction between “outer exchange value of money” (purchasing power as measured by index numbers) and “inner exchange value of money,” which is affected solely “by influences originating on the side of money,” not on the side of the other goods. Menger chooses constancy of the inner value as policy goal to be achieved by appropriately regulating the quantity of money. In a growing economy, the general price level would have a declining tendency if the money supply were kept constant – a consequence which Menger does not make explicit, and even appears not to have been aware of. There is a fundamental inconsistency in his writings, since in his essays on the currency reform of the Austro-Hungarian monarchy of 1892 Menger warned against undesired consequences of deflation and inflation. Menger’s extensive discussion on how effects on purchasing power on the side of goods could be separated from those attributable to the side of money is referred in the light of then available monetary and price statistics. The inconsistency remains enigmatic. The last part of the present contribution gives a brief overview on how authors of later generations of the Austrian School (Wieser, Mises, Schumpeter, and Hayek), who coined the term “neutrality of money” for Menger’s constancy postulate followed or deviated from Menger’s concepts of the value of money.