ABSTRACT
This chapter develops the taxonomy of collective decisions procedures that is depicted in Table 2.1. The first level of classification identifies two families of collective decision procedures, those that select an option only when all members of the collectivity agree on it (the agreement-on-outcome family), and those that select an option on the basis of prior agreement to abide by a selection procedure, whether or not the collectivity achieves complete agreement on the selected option (the agreement-on-procedure family). Within each family, four modes are identified. The agreement-on-outcome family includes the modes of consensus, pseudo-consensus, trade, and extortion. The agreement-on-procedure family includes the modes of authority, random process, voting, and contest. While some collective decision procedures involve only a single mode, others involve combinations of modes.
