Indirekte substitution kan beskrives som en form for "fordeling baseret på et andet forhold", når et sideprodukt antages at fortrænge et marginalt eller ækvivalent gennemsnitprodukt via markedsprocesser.
Indirect substitution may be modelled as a form of “allocation based on some other relationship” when a co-product is assumed to displace a marginal or average market-equivalent product via market-mediated processes.