Oh, Doug, here we go again.
> Useless in that it's done a rather poor job of explaining the
> behavior of actual economies - you know, predicting the crisis that
> never arrives.
Mattick did predict the limits of the mixed economy in the 60s!
Mystical in that I think that profit rates are
> determined more by competition,
This is Adam Smith's theory refuted by Marx. For a short summary, see Rosdolsky's short chapter. For an elaboration, see the Brenner critique by Werner Bonefeld that you offered to forward to people here last year.
> institutional/regulatory structures,
This is the same place neo liberal economics locates profitability difficulties. Which is not say it's wrong.
> and the state of the class struggle than the OCC.
This is the wage squeeze theory which even your bete noire (?)Brenner accepts through the back door: once we remove the Malthusian posit of tendentially increasing capital output ratios, he argues that there have to be real wage increases for the profit rate to fall, though they (real wage increases) result from falling prices due to intl competition instead of heightened worker power as you, Jim O'C, James Crotty and others would emphasise.
On the other hand, Moseley is able to show a rising rate of exploitation throughout the postwar period even though the profit rate has never recovered to its circa 1950s heights. Of course Moseley would put great emphasis on the increasing ratio of unprod/prod labor as contributory factor to FROP.
I would emphasise wrenching transformations in the American industrial structure as important to the *American* recovery in the profit rate (as have been declining interest rates due to global inflow of capital), but then we are no longer talking about capital as a whole which is Marx's object. The centralisation of capital also allows a quick spike in profitability from the possibilities for rationalisation it opens up; it also allows monopolies to stave off FROP at the expense of other capitals through unequal relations in the market.
Finally it can even help in long term profitability if monopolisation allows the new behemoths to slow the down the rate of accumulation by which upward pressure on the OCC is exerted (Eduard Bernstein underlined this possibility long ago: centralisation negates concentration and crisis is avoided thereby).
Here then profitability is maintained for some time but at the expense of staganation, unemployment, low rates of productivity, output and wage growth. Eventually this situtation will force another outbreak of fraticidal competition fought by the means of ever larger scale, more capital intensive investments.
yrs, rakesh