The temporal single-system interpretation (TSSI) of Karl Marx's value theory emerged in the early 1980s in response to renewed allegations that his theory was "riven with internal inconsistencies" and that it must therefore be rejected or corrected. The inconsistency allegations had been a prominent feature of Marxian economics and the debate surrounding it since the 1970s. Andrew Kliman argues that charges of inconsistency serve to legitimate the suppression of Marx's critique of political economy and current-day research based upon it as well as the "correction" of Marx's inconsistencies. Proponents of the temporal-single system interpretation of Marx's value theory claim that the supposed inconsistencies are actually the result of misinterpretation; they argue that when Marx's theory is understood as "temporal" and "single-system", the internal inconsistencies disappear. In a recent survey of the debate, a proponent of the TSSI concludes that "the proofs of inconsistency are no longer defended; the entire case against Marx has been reduced to the interpretive issue". Critics of TSSI, including David Laibman (see Criticism section below), argue that Marx intended to present what they characterize as "a structurally consistent" model of value formation in a capitalist economy with competitive profit-rate equalization. They claim that Marx's formulations fail to do this, but also what they characterize as his fundamental insights can be revealed, and extended, by means of models and concepts that emerged after his time. Instead of trying to defend the consistency of Marx's original statements, non-TSSI Marxist theorists pursue what they characterize as ever-more effective versions of what they claim to be the core theory. They also claim that they believe that Marx himself would have done this. Scope of TSSI research Among the main issues addressed by the TSSI are Marx's law of the tendency of the rate of profit to fall and the transformation of commodity values into prices of production––the so-called transformation problem––in Das Kapital Volume 3. TSSI authors have also challenged the "Fundamental Marxian theorem", which supposedly showed that Marx's value theory is unnecessary in order to arrive at his conclusion that exploitation of workers is the unique source of profit under capitalism. Other research informed by the TSSI includes studies of the impact of European economic integration, theoretical and empirical analysis of economic crisis (see Crisis), critiques of the static equilibrium methodology widely employed in economics (mainstream as well as Sraffian and Marxian), and challenges to the statistical claim that industry-level