That leaves us with a fundamental problem: fixing prices to create an equilbrium, even though equilibria only exist in textbooks. (Haven't finished with Hicks, right now I'm on Keynes, and a few
Marxist commentaries.)
From all three, they seem to be leading back to Say and Mills: supply creates its own demand. The problem is (in theoretical economics) not whether there is underconsumption, or effective demand, but whether capital can realize sufficient profit through more investment.
Redistribution, while nice for all of us, assumes equilibrium with constant productivity improvements. But the goal of capital (in the Marxist sense) is not a constant factor return -- otherwise it would be a regulated utility, which is sort of what underlies New Deal thinking. It is capital expansion (through innovation/technology, at least in part). Of course, this perspective is based on the labour theory of value.
But it seems to me to help explain why many companies are, on the face of it, immensely profitable, given their cash in the bank. To be sure, many attribute this not as hoarding, but as a lack of investable opportunities -- given low consumer demand and deleveraging.
But does consumption drive growth, or production? Do not iPhones create something new, even at prices that many consumers cannot afford? iPhones don't supply a need; they create one, and there is the value added. New Deal policies, it strikes me, try to keep everything as it was.
It seems to me (and you'll correct me, I'm sure) that Marx cottoned onto something that
neoclassical economics does not, and which the
new growth economists are trying to figure out. Let's call it, for the moment, a power law of innovation.
I find this more interesting than an industrial policy focus, which strikes me as neo-mercantilism.