A comment on John Ernst's remarks:
Maybe it isn't helpful to think of Marxist economic theory as "better",
or giving "better explanations", or being "truer" than neoclassical
theory. In the first place, since Marx allows for profit maximization and
his analysis is consistent with many theories of consumer choice, it's
not clear there is any inconsistency betwen the theories. What seems to
me to be important is that Marxist theory conceptualizes and focuses
attention on certain aspects of social reality, like class divisions, the
class distribution of produced value, and the circuit of capital, that
are invisible to neoclassical theory. The advantage of Marxist theory is
that it has a conceptual framework for studying and analyzing these
aspects of reality. In line with my earlier post, it seems to be the job
of Marxists (or more broadly, critical) economics to maintain these
concepts and our picture of these aspects of social reality at all
levels, from teaching them to beginning students, to measuring them
econometrically, to refining and better explaining their theoretical basis.
Duncan