"This paper extends earlier work (Wray 1991; see also Wray 1992b) that argued that liquidity preference theory should be interpreted as a theory of value. Here I will argue that two theories of value are needed for analysis of a monetary production economy: the labor theory of value and the liquidity preference theory of value. Both Keynes and Marx were trying to develop a monetary theory of production; Marx, of course, adopted a labor theory of value in his analysis, and it was previously argued that Keynes adopted a liquidity preference theory in his. A monetary theory of production should adopt both, however, and I will argue that Keynes seems to have recognized this. Further, Keynes did adopt labor hours as the measure of value and said he agreed that labor produces all value. I admit it is still a leap to claim that Keynes accepted both theories of value. Instead, I argue he should have adopted both and will show that this is consistent with the purposes of the General Theory."
From "Theories of Value and the Monetary Theory of Production", January 1999. Levy Economics Institute Working Paper No. 26.
For once, I feel no need to add anything.
I had completely forgotten this post by Peter Cooper:
Melting Some Marx Into MMT (March 14, 2013)