About & Methodology

We invite you to join the 2026 Cooperative Election Study!

Design

We plan a national sample stratified by state, which permits the optimal study of congressional and state races and state politics, as well as the Presidential election. The 2026 survey will be conducted on the Internet and consist of a 20-minute pre-election wave and a 10-minute post-election wave.

Content

Half of the survey content will be Common Content, administered to all survey respondents, and half of the content will be team content (10 minutes pre-election/5 minutes post-election), administered to 1,000 respondents for each team. The CES Planning Group will design the Common Content. Common Content consists of a battery of questions asked of all respondents to capture commonly asked questions, such as vote choice, as well as a handful of items for which it is uniquely advantageous to have a very large sample. Each team will design its own team content.

Deliverables

The project will deliver a 1,000-person survey covering your team’s content; a Common Content survey that consists of a subset of questions asked of all subjects; and the validated vote for most subjects in the sample, where available. Team data will be embargoed for the private use of those participating teams for a term of one year after the delivery of the survey.

Cost

We have a pending proposal under consideration with the National Science Foundation, but they have not yet informed us of whether the project will receive funding in 2026.  If we receive our requested funding, the price of a module will be $14,000. However, if we do not receive NSF support the cost will be $18,500. To join the study, please contact Marissa Shih (marissa.shih@yougov.com) at YouGov and please indicate whether your team’s participation will be contingent on the reduced price or if you will purchase a module regardless of whether we receive NSF funding. Note that there is a limit on the total number of teams that can participate in this study, so if you are considering joining, please let us know as soon as possible. 

Schedule

• July 1, 2026:  FINAL Questionnaires due to YouGov
• August, 2026: Test link to survey module sent to teams for review. Teams send edits back within 72 hours.
• October, 2026:  Pre-election survey in the field.
• Nov., 2026:  Post-election survey in the field.
• March 2027:  Survey data delivered to teams.
• Summer 2027: Voter-file matched survey data delivered to teams.

For more information, data from previous studies, and announcements, visit the CES homepage. 

For additional information about the technical details of the survey or for information on sharing a module with another team, please contact Marissa Shih (marissa.shih@yougov.com). For general questions about CES, please contact Brian Schaffner (brian.schaffner@tufts.edu).

The Cooperative Election Study (CES) is conducted by YouGov using a matched random sample methodology. In even years, the survey is fielded in two waves: pre-election (typically October through early November) and post-election (November through December). In odd years, the survey is one wave that occurs in November. 

We employ YouGov's matched random sample approach, which draws a probability sample from the target population (using American Community Survey data) and then matches each target respondent with the most similar available respondent from YouGov's opt-in panel. Matching is conducted using a weighted Euclidean distance metric based on registration status, age, race, gender, and education. This produces samples that mimic the characteristics of random probability samples while being more cost-effective than traditional sampling methods.

The sample is weighted using entropy balancing to match American Community Survey distributions on key demographics (gender, age, race, Hispanic origin, education) and their interactions. Weights are then post-stratified by additional variables including voter registration status, vote choice, and born-again status. Final weights are trimmed and normalized to equal sample size.

Quality controls are applied to completed interviews before matching to the target frame. The large sample sizes enable analysis of legislative constituencies and rare events while maintaining reasonable precision across most states.

Common Content consists of approximately 15 minutes of questions, with about 10 minutes in the pre-election wave and about 5 minutes in the post-election wave. These questions are included on all administered surveys and amount to a 60,000 national adult sample survey. Common Content is asked at the beginning of each survey.

In addition to these questions, YouGov provides demographic indicators, party identification, ideology, and validated vote.

Team Content arises from institutions who purchase modules to the CES. Each research team that wishes to be involved in the project purchases a 1,000 person sample survey which is connected to the Common Content. Common content is asked of everyone, and then each individual team determines the other half of the questions asked of its 1,000 person sample. This amounts to 10 minutes of team content on the pre-election questionnaire and 5 minutes on the post-election questionnaire. A separate dataset is produced for each team’s content.

Vote validation

The CES matches respondents to voter files for purposes of validation of survey responses, including registration status, vote history, and party registration. CES offers validated registration and vote history for every election-year survey conducted since 2006.