It is well-known that default reasoning and preference-based decision making both make use of preferential relations between possible worlds resp. alternatives. In this paper, we explore this methodological relationship in more detail by considering inference as a decision making problem. A foundational approach to preference fusion is used to define a nonmonotonic inference relation System ARS which turns out to be a refinement of System Z. We compare System ARS to other default reasoning strategies and prove that it satisfies an irrelevance property which is violated by System Z.