Cerreia-Vioglio, Ghirardato, Maccheroni, Marinacci

and Siniscalchi (Economic Theory, 48:341–375, 2011) have recently proposed a very general axiomatisation of preferences in the presence of ambiguity, viz. Monotonic Bernoullian Archimedean (MBA) preference orderings. This paper investigates the problem of Arrovian aggregation of such preferences — and proves dictatorial impossibility results for both finite and infinite populations. Applications for the special case of aggregating expected-utility preferences are given. A novel proof methodology

for special aggregation problems, based on model theory (in the sense of mathematical logic), is employed.