Analysis of Abstention in the Elections to the Catalan Parliament by Means of Decision Trees

Abstract

Democracies are based on political parties and election systems allowing voters to put the confidence in representers of these political parties to defend their interests. There are many studies analyzing the results of elections with the goal of (1) explaining the results, and (2) trying to predict what will happens in future elections. However no many attention has received the abstention, why voters do not use their right to elect representers? Commonly, abstention has not been too significant, however in last years it has been increased in many countries and it could be of great interest to analyze the causes. Studies about elections, both voting and abstention, are commonly based on statistical methods. The current paper is focused on analyzing the abstention based on symbolic learning methods (decision trees). Particularly, we are interested on identifying the groups of potential voters that have decided to abstain. We worked on data of the elections to Catalan Parliament held in 2015.