ABSTRACT

In order to elucidate some of the functions of party competition in social choice, the operation of a party system is compared with that of a direct democracy. These functions are: to reduce the requirement for citizens' participation; to obtain a more integrated policy as the social choice; to promote responsiveness of the social choice to the needs of each section of citizens; to stabilise the social choice over time; to promote consent among the citizens for the social choice. Models are then constructed to assess and compare two-party and multi-party competition in their effectiveness in performing the latter three functions. Departing from the tradition of models with a policy set placed on a left-to-right scale along which electors have single-peaked preferences, these models generate the policy set by allocation, i.e. the set of alternatives out of which each competing party chooses its policy, consists of variations in the allocation of the nation's limited resources between the needs of the various sections of electors. A further feature of the models is that electors are influenced in their voting decisions not only by party policy, but also by their “party identification”, which, as in the real world, may vary in strength from elector to elector. It is shown that, with two-party competition, there is an equilibrium policy on which both parties converge. This is that policy which, for either party, maximises its votes by allocating the resources between the sections of electors so that the marginal return in votes for resources is the same for 350each section. With multi-party competition, however, different parties tend to diverge in policy; the policy of the government coalition is indeterminate, since it is uncertain which parties will form the coalition, and what will be the result of the bargaining between these parties concerning the policy they will jointly adopt. It is concluded that, as represented by the models, multi-party is less effective than two-party competition in performing the last of the three functions in social choice stated above. A third type of party competition, that for majority preference in a multi-party situation, is then described. This is provided by an electoral system in which preliminary ballots are used to reduce the number of competing parties to two, the government party then being elected in a final ballot between these two parties. Under this system, despite the multi-party context, the government party faces competition similar to that in a two-party situation.