Are More Heads Better Than One, or a Few?
http://blog.oup.com/2008/12/one_few/
In countless settings, an important question of institutional design involves the size of the group that will be charged with making a decision. Some of these settings are political. How many legislators should sit in Congress? Should we have a single President, or an executive council? Should administrative agencies be advised by panels of experts, and if so, how many experts should the panel contain? Some of these settings arise in personal life, and in markets. Should one accept the diagnosis of a single doctor, or is it better to consult a team of doctors? If one is to make a major life decision, is it better to take the advice of a single trusted friend, or to consult widely?
Of course these settings are heterogeneous, and the issues are complex. An important question is whether we care not only about the accuracy of the decision but also about the cost of decision making (including the time it takes to make the decision, or its opportunity cost). For simplicity, however, let us focus solely on cases in which the cost of decision making is not important and in which accuracy is well-defined. The classic case involves a criminal verdict of innocent or guilty. Should the verdict be issued by a single person (perhaps a judge), or by a multi-member panel (typically a jury?) If we use a jury, should it have six members, or twelve, or some other number? Or perhaps we might have differently sized juries for different issues.
