Michael Perelman writes: >... we have no way of calculating the abstract labor
values of already installed constant capital unless we have a scientific means
of measuring depreciation.<
there is more than one way to measure depreciation, but there is a way to
measure the value of already-installed constant capital, i.e., at reproduction
cost (measured in value terms). This may be difficult in practice, but in
principle it could be done.
Even it something can't be measured doesn't mean that we can't use a theory in
order to understand the stuff that can be measured. That theory may involve
magnitudes ("intervening variables") that can't be measured. Science is more
than measurement.
More importantly, at least for how I interpret Marx's law of value, it's only
new value (value-added) that counts. The key to value theory is not some
relationship between prices and values (the so-called transformation problem)
but instead the relationship (1) between total new value and the same magnitude
in price terms and (2) between total surplus-value and total capitalist
property income.
JD
