This paper presents a framework for measuring productive transformation directly in physical units, without monetary abstraction, and without recourse to subjective valuation. Productive activity is dened as the physical realisation of an algorithm under a specied constraint, measured via causally required energy throughput: the action integral over all energy ows required by the algorithm's execution. The system boundary is determined by the algorithm itself, not by the analyst. Efficiency emerges as deviation from least-action realisations within the set of algorithms that satisfy the same constraint.
Steve Kelsey (Fri,) studied this question.