We reconsider the theory of Thompson aggregators proposed by Marinacci and Montrucchio. We prove a variant of their Recovery Theorem establishing the existence of extremal solutions to the Koopmans equation. We apply the constructive Tarski-Kantorovich Fixed Point Theorem rather than the...

We reconsider the theory of Thompson aggregators proposed by Marinacci and Montrucchio (2010). We demonstrate the Koopmans equation has a unique utility function solution given a Thompson aggregator. Uniqueness holds only on the interior of the commodity space's positive cone. We verify Du's...