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The BES Post-Election Random Probability Survey V.1.0.0: Release note

The British Election Study Team

This note accompanies the release of the 2019 BES Post-Election Random Probability Survey (version 1.0.0).

Dataset and documentation

The dataset and additional documentation are available to download here.


Fieldhouse, E., J. Green., G. Evans., J. Mellon, C. Prosser, R. de Geus, and J. Bailey (2021) 2019 BES Post-Election Random Probability Survey v.1.0.0 [computer file], January 2021.

The face-to-face survey

The 2019 BES Post-Election Random Probability Survey is an address-based random probability sample of eligible voters living in 844 wards in 400 Parliamentary Constituencies in England, Scotland, and Wales. 3,946 people completed the survey. As the coronavirus crisis occurred partway through the data collection process, it was not possible to interview all respondents face-to-face in their own home. In total, 2,095 respondents (53.1%) were interviewed using computer-assisted personal interviewing (CAPI). All further respondents completed either a push-to-web survey (1,350 respondents; 34.2%) or a mail-in survey (501 respondents; 12.7%). More information on the accommodations made to the data collection process due to the pandemic can be found in the technical documents that accompany the data.

Fieldwork for the face-to-face portion of the data collection was conducted by Ipsos and NatCen between 21st December 2019 and 18th March 2020. Likewise, data collection for the push-to-web portion of the survey occurred between 29th April 2020 and 13th July 2020. Dates for the mail-in survey are not available due to the potential difference between the time that the survey was completed and when it was received, though we do include data on when these data were scanned.

The dataset also includes a self-completion Comparative Study of Electoral Systems (CSES) module that was answered by 2,537 respondents. Full details of the methodology and fieldwork are available in the technical report that accompanies the data release. Full details of the questionnaire can be found in the codebook which also accompanies the data release.


To ensure that the BES face-to-face survey is representative of the population (18+ adults in Great Britain who are eligible to vote) the data were weighted. Three weights were applied: design weights to correct for unequal selection probabilities, demographic weights which account for differing levels of response from various groups in the population, and result weights which account for differing levels of response from voters and non-voters. We recommend using the results weights (wt_vote).

The data file contains 7 weight variables, as follows:

  • wt_sel_wt: Weight: Selection weight (including capping)
  • wt_demog: Weight: VEP demographics
  • wt_vote: Weight: VEP Self-reported vote
  • wt_demog_f2f: Weight: VEP demographics (Face-to-face only)
  • wt_vote_f2f: Weight: VEP Self-reported vote (Face-to-face only)
  • wt_demog_cses: Weight: VEP demographics (CSES only)
  • wt_vote_cses: Weight: VEP Self-reported vote (CSES only)

Future releases

At the time of the release of version 1.0.0 of the data, two tasks are still ongoing which will affect future releases of the data and some analysis of the current data:

  • We will be adding occupational class measurements
  • We will be adding a restricted access file to the UK Data Service that contains small-area location data

The British Election Study

The British Election Study 2019-2023 is managed via a consortium of the University of Manchester and the University of Oxford. The British Election Study Team is comprised of Ed Fieldhouse, Jane Green, Geoff Evans, Jon Mellon, Chris Prosser, Roosmarijn de Geus, and Jack Bailey. The BES 2019-2023 is working in close collaboration with colleagues within the Universities of Manchester and Oxford, and is partnering with a wide variety of affiliated datasets and projects (and proposed projects) to link BES voter data to other data on election candidates and campaigns.