La Falla de las Encuestas en las Elecciones Argentinas de 2019. Un Análisis en Perspectiva Comparada Internacional (The Failure of the Polls in the 2019 Argentine Elections. An Analysis in International Comparative Perspective)

Abstract (English): The performance of polls in the 2019 Argentine elections reached its lowest point since democratic restoration in 1983. Their errors were much greater than those observed in recent years in mature democracies, where there is talk about a crisis of this type of surveys. In the primaries, Argentine pollsters widely underestimated the advantage of the Everyone's Front opposition alliance over the governing Together for Change. But after adjusting their methods, in the general election they overestimated that advantage by similar margins. We analyze both failures in an international comparative perspective. Vote intention data for president was used to calculate error indicators and compare them with current international averages and those of past decades, and with errors in several electoral cycles in the US and the UK. We examine ongoing changes in the survey industry, falling response rates, and causes of error identified by new academic studies and work commissioned by professional associations in the field of public opinion research. This literature shows that pre-election polls are no more inaccurate today than in the past and underlines the importance of "non-sampling" errors, particularly those produced by non-response bias, when the probability of participating in a poll is lower for certain groups, such as people with little interest in politics or low social or institutional trust. These types of errors and their causes are now better understood and procedures can be designed to improve the accuracy of estimations. We also discuss the impact of inaccurate polls on political strategies and the media narrative of elections, as well as the difficulty for pollsters, journalists and political actors to acknowledge and communicate the levels of uncertainty associated with electoral predictions. Our analysis highlights basic limitations of the polling industry and public opinion research in Argentina, such as the lack of a professional association and the incipient development of electoral behavior studies. Pollsters were surprised when voters punished the government because of the economic crisis, even though it was the most likely scenario according to a not very large but significant set of empirical studies on economic voting in Argentina and Latin America. The substantial errors in 2019 have implications for the reliability of issue polling, which may show a distorted picture of opinions in Argentine society.