INFORMATION POOLING THROUGH MAJORITY-RULE VOTING - CONDORCETS JURY THEOREM WITH CORRELATED VOTES

Does majority-rule voting steer an imperfectly informed assembly of people towards the full-information outcome? Condorcet's jury theorem provides an affirmative answer under certain conditions. A key condition is that the votes be statistically independent; however, it is unrealistic, and hence, unacceptable. This paper generalizes the jury theorem to certain general models of correlated voting, viz., normal, hypergeometric and Polya distributions. The paper proves that the effectiveness of majority-rule voting decreases as the correlation between votes increases. Potential applications are indicated.