A brief note on a further refinement of the Condorcet Jury Theorem for heterogeneous groups

I extend Boland's (1989) work on the Condorcet's Jury Theorem (CJT) for heterogeneous groups. I demonstrate that, as long as CJT holds (in that the mean individual competence ≥(1/2)+(1/2n)), heterogeneous groups are better at making the correct decision than homogeneous groups for any given level of mean competence. I also extend CJT to collective decision rules other than simple majority, and show that CJT holds for groups with supermajority decision rules if the mean individual competence is at least (π(n+1)/n) (where π=required majority).