Sylvester Kollin

14 karmaJoined Oct 2022Pursuing an undergraduate degree


Maths undergrad. Inter alia interested in decision theory, formal epistemology, s-risk reduction. Also on LessWrong.


Topic Contributions

There is also the evidentialist consideration (see e.g. section 5 of Leslie [1991]): to cast your vote plausibly gives you evidence that others decided to do so as well. The correlation between you and any given person is of course very low, but if the population is sufficiently large then the effect could be substantial.[1]

  1. ^

    However, this is not necessarily an argument in favour of voting since you might be more correlated with people who would vote for the other party.

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):

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.