An assessment of the causes of the errors in the 2015 UK general election opinion polls

Patrick Sturgis, Jouni Kuha, Nick Baker, Mario Callegaro, Stephen Fisher, Jane Green, Will Jennings, Benjamin E. Lauderdale and Patten Smith

Journal of the Royal Statistical Society Series A, 2018, vol. 181, issue 3, 757-781

Abstract: The opinion polls that were undertaken before the 2015 UK general election underestimated the Conservative lead over Labour by an average of 7 percentage points. This collective failure led politicians and commentators to question the validity and utility of political polling and raised concerns regarding a broader public loss of confidence in survey research. We assess the likely causes of the 2015 polling errors. We begin by setting out a formal account of the statistical methodology and assumptions that are required for valid estimation of party vote shares by using quota sampling. We then describe the current approach of polling organizations for estimating sampling variability and suggest a new method based on bootstrap resampling. Next, we use poll microdata to assess the plausibility of different explanations of the polling errors. Our conclusion is that the primary cause of the polling errors in 2015 was unrepresentative sampling.

Date: 2018
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
https://doi.org/10.1111/rssa.12329

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:bla:jorssa:v:181:y:2018:i:3:p:757-781

Ordering information: This journal article can be ordered from
http://ordering.onli ... 1111/(ISSN)1467-985X

Access Statistics for this article

Journal of the Royal Statistical Society Series A is currently edited by A. Chevalier and L. Sharples

More articles in Journal of the Royal Statistical Society Series A from Royal Statistical Society Contact information at EDIRC.
Bibliographic data for series maintained by Wiley Content Delivery ().