# Governability and Representativeness:: Simulation of Concrete Voting Situations

• Autores: Vito Fragnelli , Giovanni Monella, Guido Ortona
• Localización: Abstracts of the Fifth Spanish Meeting on Game Theory and Applications / coord. por Jesús Mario Bilbao Arrese , Francisco Ramón Fernández García , 2002, ISBN 84-472-0733-1, pág. 45
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • When we elect a Parliament, we decide not only who will represent us, but many other things too: first of all, obviously, who will govern us, and some �hows� of that. The result depends crucially on the electoral rule we use. In other words, the choice of the electoral rule is relevant for many goals. A very rough survey of (some) literature can count up to seventeen items. Can we properly evaluate the effect of an electoral system on a goal? In principle, the answer is yes.

    The first step is to elaborate a suitable and measurable index for that goal;

    next, all what we need is to compute an estimation of the value of the index for different systems. This can be done through simulation. What above does not allow to pinpoint the �best� electoral system; on the contrary, it goes very close to prohibit it. The obvious reason is that the choice of an electoral system affects specifically many goals, possibly all; hence, the choice of the �best� electoral system crucially depends on the weight assigned to each specific goal.

    An electoral system X that performs better than another system Y on all goals dominates Y , and hence excludes Y from the choice; but X may be considered the best one only if it dominates all the other systems. In general this never happens, mostly because systems that perform well on goal A usually perform poorly on goal B, and vice versa, as we noticed above. However, this is not the right approach to find out the best electoral system. The rank of a specific goal (as measured by a suitable index) is a function of different characteristics of the choice process; the electoral system is only one of them. Let us consider (not only for sake of simplicity) only two indices, commonly recognized to be the most relevant ones: the degree of correspondence to the choices of voters (representativeness) and the efficiency in government (governability), denoted by G and R. With a suitable definition of the two indices it is possible, by a simple empirical rule, to choose the best electoral system.

    We need three elements: colleges, parties and constituents. Colleges and parties can be identified by a number in the interval [-1, 1], where -1 indicates an extreme left position, 1 an extreme right one and 0 a central one.

    A constituent profile is characterized by the complete sequence of its political preferences, expressed from a sequence of hexadecimal numbers. The program works on a hypothetical country formed by 100 colleges and produces as output a parliament. It�s possible, selecting the parties, to define a majority and to have the relative indices of governability and representativeness. It�s possible to choose ten different electoral systems.

    Finally a new electoral system was implemented: the VAP (Votum A Posteriori in Latin) system (Ortona, 2001). It runs through two stages. In the first one, the parliament is elected with a proportional system (e.g. perfect proportionality), in order to maximize the representativeness. Note that some parties are labelled as relevant. When a majority forms the Government, its confidence vote is as usual, except that from this moment on, the votes of the members of the relevant parties in the majority have a voting weight larger than 1, if they vote accordingly to the Government. These parties are labelled as crucial. This is a kind of majority premium that is not applied if the members act against the Government. This electoral system increases the stability as it punishes defections from the majority.