Voter turnout in Portugal: a geographical perspective

Dissertation presented as the partial requirement for obtaining a Master's degree in Statistics and Information Management, specialization in Information Analysis and ManagementThe decline of voter turnout in Portugal has been confirmed in the last legislative election of 2015. This fact, together with the unquestionable democratic value associated with the act of voting, leads to the discussion of the issue and emphasizes the need for additional investigation concerning the portuguese context. Particularly, it is crucial to identify the characteristics of citizens who vote, to better understand the phenomenon and think about solutions. This work aims to identify the most significant sociodemographic variables in explaining voter turnout in continental Portugal and describe the relationship between those variables and voter turnout, including the geographical variation existing across the municipalities. Data related to sociodemographic variables are provided from population census 2011, and turnout results concerns the legislative election of the same year. The chosen variables have been addressed in literature, both in meta-analyses studies and in country level empirical investigation. The analysis starts with the conventional Ordinary Least Squares (OLS), and continue with more spatially sensitive methods, namely Geographically Weighted Regression (GWR) and its semiparametric extension (SGWR). The final method, SGWR, enables the investigation of local variations in turnout values, simultaneously considering that its relationship with some variables might not vary over space. Results show that turnout is a complex process, influenced by a set of sociodemographic variables. While some variables affect turnout differently over the country (percentage of family cores with children aged less than 15, and percentage of owner-occupied houses), others affect it uniformly (percentage of graduated residents, percentage of classic families, and distance to Lisbon or Oporto – the nearest). This highlights the use of a semiparametric approach to better understand turnout and for further research on voting issues