Social Software Mini-conference 

Abstract: Judgment aggregation problems are language dependent in that they may be framed in different yet equivalent ways. We formalize this dependence via the notion of translation invariance, adopted from the philosophy of science, and we argue for its normative desirability. We characterize the class of translation-invariant aggregation functions in the canonical judgment aggregation model which requires collective judgments to be complete. Since there are reasonable translation-invariant aggregation functions, our result is a possibility theorem. At the same time, we show that translation invariance does have certain normatively undesirable consequences (e.g., failure of anonymity) which can only be circumvented by moving to a more general model of judgment aggregation, one that allows for incomplete collective judgments. Joint work with Fabrizio Cariani and Josh Snyder.