  Foreign exchange markets show that currency units (= accounting or nominal
price units) are variables. Technical and economic progress evidence that the
consumer baskets (= purchasing power units or real price units) are also
variables. In contrast, all physical measurement units are constants and either
defined in the SI (= metric) convention or based upon natural constants (=
"natural" or Planck units). Econophysics can identify a constant natural value
scale or vaue unit (natural numaraire) based upon Planck energy. In honour of
the economist L. Walras, this "Planck value" could be called walras (Wal),
thereby using the SI naming convention. One Wal can be shown to have a
physiological and an economic interpretation in that it is equal to the annual
minimal real cost of physiological life of a reference person at minimal
activity. The price of one Wal in terms of any currency can be estimated by
hedonic regression techniques used in inflation measurement (axiometry). This
pilot research uses official disaggregated Swiss Producer and Consumer Price
Index data and estimates the hedonic walras price (HWP), quoted in Swiss francs
in 2003, and its inverse, the physical purchasing power (PhPP) of the Swiss
franc in 2003.
