Originally published in Inside the Influence Industry's Personal Data: Political Persuasion - How it works by Tactical Tech's Data & Politics team.

What are voter files?

Voter files are profiles of individual voters that are collected into databases for political campaigning purposes. In its most basic form, a voter file is a list of people who could potentially vote in a given election. This data can also be combined with more detailed information, like party affiliation or registration history. While voter files can vary depending on who produces them - whether electoral administrators, commercial entities or political parties - they often consist of publicly accessible information combined with more detailed data acquired from outside sources and polling.

While governments use voter files for managing voter eligibility, political parties---often in collaboration with digital consultants or data brokers---use this information in their campaign strategising. Voter files provide a good basis to calculate support for their candidates or causes, as well as to help identify supporters and target undecided voters for conversion, among other uses. Voters' contact information also plays a crucial role in campaign messaging, as it can be used for 'get out the vote' initiatives, to seek volunteers and donations and inform and mobilise supporters.

The value of voter files as an asset to campaigns has increased considerably due to advances in methods for collecting, analysing and utilising vast amounts of personal data. In the last few decades, voter files have benefitted from the market for personal data and have been enhanced by more consequential data sources than the basic information gleaned from electoral rolls. This supplementary data helps campaigns better understand demographic patterns and the voting habits of individuals. Additional data points can be used to create granular, personalised profiles, which are useful in a campaign's predictive analysis. This includes tracking a voter's past turnout and party affiliation to index their sentiment and even utilising relevant financial data such as credit reports, consumer data and other socio-economic indicators. The additional information also helps political campaigns tailor messaging to voters' individual interests.


This screenshot from GitHub shows fields belonging to US voter registration data.

Source: https://github.com/pablobarbera/voter-files/blob/master/README.md, accessed 11 March 2019.

To illustrate the granularity of data offered by brokers of voter files, the US-based firm HaystaqDNA offers a 'must-have' list of political issues that they claim their data can resolve for individual voters. These include the latest hot-button issues such as presidential approval and immigration policy, support for activist groups and movements such as Black Lives Matter or Momentum, as well as consumer habits such as being a rideshare user. The scope of voter preferences offered by HaystaqDNA not only shows how voter files now seek to gauge the finer points of voter sentiment, but also exemplifies the shift in the composition of voter files: they are no longer solely developed by political parties, but also by data brokers and digital consultants, many of whom specialise in political data. For example, the data broker NationBuilder offers free voter files for 190 million US voters including their phone numbers, addresses, voter history and sometimes email addresses, acquired from government offices for substantial fees, before being standardised and enhanced by the company. This fine-tuning, they claim, allows them to offer a comprehensive voting history that tracks voter participation in 'any type of election... from football club to parliament'.


A screenshot from the website of the data firm HaystaqDNA, showing a sample of political data on voters that they offer.

Source: https://haystaqdna.com/politicalhq/, accessed 19 February 2019.

Where do they get the data?

Parties can build their voter files from four main sources: electoral registers, polls and surveys, party membership registers, online public data or commercial data brokering companies.

Voter registration records: This data can be gathered from an electoral register kept by the local electoral district as a record of who is registered to vote. For example, in the United Kingdom, the local registration officers keep two registers: the electoral register and the open register. Election staff, political parties, candidates and holders of elected office can access this data for 'electoral purposes'. Before elections or referendums the registers are sent to official campaigns for use to send out promotional material. The open register, which citizens can opt out of, can be bought by any person, company or organisation for any reason. Similar data is made available in many countries, varying in accordance with national data protection laws.

Polls or surveys: This data is gathered by surveying methods, from simple online polls and political apps to labour-intensive methods such as phone-banking or door-to-door canvassing. Increasingly, contacting voters over the phone relies on technologies such as robocalling. Volunteers will usually follow a script and ask individuals about their political party preferences or, during referendums, opinions on the ballot question, such as marijuana legalisation. Their responses are then recorded, often using canvassing apps. They may also score other metrics such as 'persuadability' based on their interactions.

Data brokers: Data brokers collect voter data and create voter profiles through various means, including the electoral databases mentioned above, surveys and from other commercial data. Data brokers often offer other services for political parties, such as software to manage their databases, referred to as constituent or customer relationship management systems (CRM). One company, NationBuild, apart from streamlining public data for use in campaigns, can ensure the database has the most up-to-date data and can enhance basic voter information with additional commercial data, such as financial information or hobbies and interests. Another provider, L2, offers basic data as well as occupation, likely primary language and views on hot-button political issues in the US such as same-sex marriage and gun control.

Political party membership: In many countries, political parties keep registers of the members of their party. Apart from contact information, this history might include an individual's length of membership in the party, their voting records for party leadership, history of volunteering for the party and donations. Parties can use various technological tools to engage with members with the specific aim of collecting further data on them, including through canvassing apps or social media polls. In some countries, such as Kenya, this data must be shared with the government, whereas in others, such as the UK, it is up to the party if they want to publish the data or statistics from the data.


A screenshot from the company L2, which offers voter file enhancements including lifestyle data and opinions on political issues.

Source: https://www.l2political.com/products/data/voter-file-enhancements/, accessed 11 March 2019.

Some examples

In Chile: The electoral register in Chile is freely accessible online as a PDF after the Chilean electoral service declared that it should be made public. The database contains information for all Chileans over 17 years old. In line with standard electoral rolls, this data includes names, unique voting number, gender and address. While regulations prohibit commercial uses of the database, there are few other limitations. Privacy concerns have been raised in response to the publication of this information due to the lack of security around the information and how easy it is to reproduce the database. Further, Chilean privacy law has not always been enforced in other spheres. Any political campaigning group can use the information as a foundation for their voter files.

In Kenya: There are various sources to help political parties and candidates in Kenya to form their own voter files. In 2017, mass voter registration was carried out by Kenya's Independent Electoral and Boundaries Commission (IEBC). Voters were required to present their national ID card, give fingerprints and have their photo taken at the local polling station. This registration was then made publicly available - usually in printed form, and placed somewhere central to each voting region. If a political candidate wanted the data earlier, they could pay for it. This option was particularly useful as the open publication was delayed for several months, and when it finally appeared was found to be riddled with errors.

In Canada: Political parties in Canada are exempt from privacy laws. Therefore, each political party can keep voter files without needing to adhere to the same laws that regulate businesses' collection of data. By expanding these data sources and developing better analytics, the parties refine their categories of voters according to supporters, non-supporters or undecided. For example, the Conservative Party of Canada use this data to create a scale from -15 to +15 to rate how much an individual supports them, while the Liberal party have a tier system rating from 1 (supporters) to 10 (those who may be hostile). In the deregulated environment there is little transparency about exactly what data the databases contain or what modelling is performed to assess the final ratings of support levels.


A screenshot of the Canadian Conservative Party’s scale of different voter support-levels, ranging from non-supporter (-15) to supporter (+15).

Source: https://ourdataourselves.tacticaltech.org/media/ttc-influence-industry-canada.pdf, accessed 7 March 2019.

In the UK: Each party in the UK maintains its own voter file, therefore they differ greatly depending on the resources and technical expertise of the party itself. The Labour Party has in-house database software called Contact Creator, which contains data on preferences, interests, voting behaviour and socio-economic information. Contact Creator hosts any data collected by phone, email or door-to-door canvassing. The Liberal Democrat's database, Connect, was developed by NGP VAN, the same providers of database software for the Democratic party in the US. Candidates and parties with fewer resources, however, were found to be using much less sophisticated, self-created software and maintained Excel spreadsheets to host supporter information.


A screenshot of the UK Labour Party’s voter database Contact Creator shown above has an option to input data generated from campaign contact with individual voters.

Source: The Labour Party. ‘Contact Creator, The Essentials’, 2017, accessed 11 March 2019.

How do I know if I'm part of a voter file?

It is very difficult to determine how you are documented by the various actors and entities that maintain, enhance and distribute voter files. There is rarely any obligation for parties to publish any information regarding their data assets. Nevertheless, there are some sources that could be referenced if you want to check how your personal details are represented. The primary source is the general electoral registers. Each country has different regulations about electoral registers - but those that are public, such as in Chile and Kenya, make it easy to verify what personal data is accessible. The UK and the US similarly make basic information of any registered voter available to the public. A deeper look at communications received from political organisations could additionally provide clues about what personal data has been collected. This includes post and email, as well as visits from canvassers, phone calls or robocalls from political organisations.


↘ Voter files allow political parties to understand how to use their limited resources, as voter databases can help decide which messages to deliver to which individuals, depending on their support, opposition or undecided attitude towards the party.

↘ The more detailed databases can help political organisations provide voters with information related to their specific interests such as education, the environment or welfare.

↘ Voter files allow political parties to assess the levels of diversity in their membership and focus outreach efforts on any areas lacking representation.

↘ They can also help political parties better understand their members to develop policy positions based on the interests of local residents.

↘ When national-level voter databases are available to all parties, it helps create an equal playing field; however, political parties with more money, resources and technical expertise are able to enhance this basic information with sophisticated data gathering and analytics, giving them a competitive advantage.

↘ Databases are expensive and time-consuming to keep up-to-date. Therefore, they may contain errors and obsolete information, as in the case of electoral registers in Kenya. In the UK, the Labour Party and Conservative Party have had issues with their databases, from persistent glitches to crashes.

↘ There are several cases of voter files being leaked (or otherwise acquired through illegal methods), with a negative effect on voter privacy.

↘ These databases are assets that can vary greatly between political parties. This may result in an uneven playing field that negatively impacts the power dynamics of democratic systems.

Author: Amber Macintyre