Reply to John Ernst:
Maybe the first thing to do to sort these issues out is to locate the
problem of moral depreciation theoretically. It seems to me it's an issue
of how capitalists compete: if they anticipate more rapid obsolescence of
capital in one sector than another, they will require a higher profit
rate in the first sector to compensate for their anticipated capital
losses. On the other hand, it doesn't seem to affect the new production
of value by living labor.
Duncan