Improving opinion poll reporting: the Irish Polling Indicator

Abstract

This article describes a statistical method for aggregating the information from Irish opinion polls. Such aggregate estimates provide academic researchers with a time series of support for political parties, and inform the public better about opinion polls by focusing on trends and uncertainty in these estimates. The article discusses the challenge of aggregating opinion polls in a multi-party setting with a comparatively limited number of polls available and presents daily estimates of party support for the 1987–2016 period. The article develops a method to better model major sudden political and societal events, which have been common in Ireland since 2007. Finally, it discusses how polling aggregation estimates can enhance opinion poll reporting in the media.