Over the past decade, an increasing number of authors have been examining the nexus of producer versus consumer responsibility, often dealing with the question of how to assign responsibility for internationally traded greenhouse gas emissions. Recently, a similar problem has appeared in drafting the standards for the Ecological Footprint: While the method traditionally assumes a full life-cycle perspective with full consumer responsibility, a large number of producers (businesses and industry sectors) have started to calculate their own footprints (see www.isa.org.usyd.edu.au). Adding any producer's footprint to other producers' footprints, or to population footprints, which all already cover the full upstream supply chain of their operating inputs, leads to double -counting: The sum of footprints of producers and consumers is larger than the total national footprint. The committee in charge of the Footprint standardisation process was hence faced with the decades-old nonadditivity problem, posing the following dilemma for the accounting of footprints, or any other production factor: if one disallows double -counting, but wishes to be able to account for producers and consumers, then one cannot impose the requirement of full life-cycle coverage; the supply chains of actors have to be cur-tailed somehow in order to avoid double-counting. This work demonstrates and discusses a non-arbitrary method of consistently delineating these supply chains, into mutually exclusive and collectively exhaustive portions of responsibility to be shared by all actors in an economy.