Statistica Applicata - Italian Journal of Applied Statistics Vol. 25 (1) 39 THE ITALIAN POLITICAL AND PRE-ELECTION POLLS OVER TIME: A DATA QUALITY ANALYSIS Claudio Quintano, Antonella Rocca, Alfonso Carfora 1 Department of Management and Quantitative Studies - University of Naples Parthenope, Naples, Italy Received: 30 h May 2014/ Accepted: 24 th July 2015 Abstract. In the last decades, political and pre-election polls have been assuming more and more importance because they measure not only support for political parties and candidates, but also public opinion on a wide range of social and political issues. When conducted through a scientific design, they are a powerful political and democratic instrument. Nevertheless, in Italy, a set of “best practices” about their quality is likely to remain elusive. In this paper, according to the AGCOM resolutions, an analysis on the qualitative content of all the Italian political and pre-election polls from 2000 to 2012 is proposed, with the aim to evaluate their reliability and to draw an identikit of high quality polls. Keywords: Political and pre-election polls, Reliability, Quality and Completeness indexes. 1. INTRODUCTION In these last years, political polls, particularly the pre-election ones 2 , have been assuming more and more importance because they represent a useful source of political information both for politicians and voters, helping to translate public preferences into policy, giving decision makers impartial information about what the public wants, and helping people to understand where they fit into the political system (Corbetta and Gasperoni, 2007). With reference, specifically, to the pre- election ones, they can be viewed as surveys finalized to document the overall state voting population demographic and nowadays represent one of the main expression of participative democracy, performing a legitimate political informative function vis-à-vis voters, conveying the election “supply and making known, within limits, the corresponding demand. 1 Claudio Quintano, email: quintcla@hotmail.com 2 In this work, all the political polls, including both the pre-electoral ones, finalized to test vote intentions, and opinion polls on political and economic facts are analysed.