A recent and related paper: Jeffrey Pooling by Pettigrew and Weisberg. Abstract (bold emphasis mine):
How should your opinion change in response to that of an epistemic peer? We show that the pooling rule known as “upco” is the unique answer satisfying some natural desiderata. If your revised opinion will impact your opinions on other matters by Jeffrey conditionalization, then upco is the only standard pooling rule that ensures the order in which peers are consulted makes no difference. Popular proposals like linear pooling, geometric pooling, and harmonic pooling cannot boast the same. In fact, no alternative to upco can, if it possesses four minimal properties—properties which these proposals all share.
Also, Pooling: A User’s Guide by the same authors. Abstract (where Upco is one specific multiplicative method):
We often learn the credences of others without getting to hear the evidence on which they’re based. And, in these cases, it is often unfeasible or overly onerous to update on this social evidence by conditionalizing on it. How, then, should we respond to it? We consider four methods for aggregating your credences with the credences of others: arithmetic, geometric, multiplicative, and harmonic pooling. Each performs well for some purposes and poorly for others. We describe these in Sections 1-4. In Section 5, we explore three specific applications of our general results: How should we understand cases in which each individual raises their credences in response to learning the credences of the others (Section 5.1)? How do the updating rules used by individuals affect the epistemic performance of the group as a whole (Section 5.2)? How does a population that obeys the Uniqueness Thesis perform compared to one that doesn’t (Section 5.3)?
A recent and related paper: Jeffrey Pooling by Pettigrew and Weisberg. Abstract (bold emphasis mine):
Also, Pooling: A User’s Guide by the same authors. Abstract (where Upco is one specific multiplicative method):