I agree essentially with the importance of the points John Ernst raises. (He,
however, is too critical of his own contribution [1982 RRPE value theory
issue]. Whatever its incompleteness, it was a pathbreaking work which DEMANDS
much more attention and recognition than it has recieved.)
I especially think that the *discrepancy* between historical and replacement
costs is a crucial one for understanding crises, in general and especially
today. Those of us who think in terms of historical values must also acknowledge, and work out, the processes by which devaluation (depreciation, devalorization) of capital occurs, so that replacement costs do matter. This work has only
begun. In addition to Michael Perelman's book, I would also recommend his
1993 _Rethinking Marxism_ article in this regard.
Andrew