John Weeks 
Irreconcilable Inconsistencies of Neoclassical Macroeconomics [PDF ebook] 
A False Paradigm

In the course of this book it is argued that the loss of what is essentially "macro" in Keynes is the result of a preference for a form of equilibrium analysis that gives unqualified support to the ideology of free markets. In the case of Marx, his theory of exploitation and from this the stress on class struggle, led to an almost complete neglect of his contribution to the analysis of the aggregate demand and supply of commodities.