The program for the simulation of electoral systems ALEX4.1: what it does and how to use it.

This paper illustrates ALEX4.1, the 2007 version of the program of simulation of electoral systems developed at ALEX, the Laboratory for Experimental and Simulative Economics of the Università del Piemonte Orientale at Alessandria, Italy. The main features of the program have been described with reference to a previous version in Bissey, Carini and Ortona, 2004; the paper may be freely downloaded from the site of the journal where it has been published, or in its working paper version from the site http://polis.unipmn.it/. The organization of this paper is, consequently, rather unusual. The next section presents only the very basic traits of the simulation program, as most details and theoretical considerations may be read in the quoted (and easy-to-find) reference. Sections 3 and 4 are the most important: they illustrate the novelties of ALEX4.1 with respect to previous versions. Section 5 is very short, as it contains only the instructions for downloading the program, and some caveats regarding its use. The core of the paper is a large appendix that contains the readme file of the package ALEX4.1. Actually, this paper should be considered a handbook for the use of ALEX4.1.