This collection focuses on a long-running debate over the logical validity of Karl Marx's theory that exploitation is the exclusive source of capitalists' profits. The "Fundamental Marxian Theorem" was long thought to have shown that orthodox Marxian economics succeeds in replicating Marx's conclusion. The debate begins with Andrew Kliman's disproof of that claim. On one side of the debate, representing orthodox Marxian economics, are contributions by Simon Mohun and Roberto Veneziani. Although they concede that their simultaneist models cannot replicate Marx's theory of profit in all cases,...