Independence Revisited
Keyword(s):
The Independence Assumption is the most misunderstood premise of the Condorcet Jury Theorem. This chapter shows, first, that absence of direct voter interaction is neither necessary nor sufficient for Independence. Second, we explain that the statistical independence required is conditional: in Condorcet’s jury theorem, conditional on the state of the world; in other jury theorems, conditional on the evidence, on common causes, or on the whole decision situation. This insight leads, third, to the ‘Best Responder Corollary’, a jury theorem that is better suited to dealing with the inevitable interdependence of votes caused by common causes. In the final section, we discuss epistemic implications.