Purdue students use mathematics to forecast U.S. elections in real time
10-25-2024
Students studying mathematics and computer science at Purdue University are using mathematical modeling to forecast the 2024 United States elections. They are using publicly available polling data to determine model parameters. This undergraduate research project is led by Alexandria Volkening, assistant professor of mathematics in Purdue University’s College of Science. The team has developed a website named cRUD (compartmental Republican–Undecided–Democratic model for forecasting U.S. elections).
“At its core, our model is a compartmental model,” says Volkening. “We consider different voter groups and specify rates for folks becoming undecided or of interacting with a committed voter and changing their opinion. Compartmental models are common in studies of disease transmission (i.e., the SIS, Susceptible–Infected–Susceptible, model), but very flexible, and we play on this with our ‘cRUD’ website. Our model, based on a paper my collaborators and I published in 2020, performs similar to popular forecasters at predicting elections in the last two decades when we back check it.”
The website allows a user to look at forecasts for the president, Senate, and governor elections. The group’s work involves determining model parameters using the time trajectory of publicly available polls and simulating 10,000 possible elections with their mathematical model. Their forecasts are then loaded on the website. Volkening’s team of undergraduate students (Joseph Cromp, Thanmaya Pattanashetty, and Alexia Rodrigues) provide their source code on the website for anyone to use or build upon. Cromp and Rodrigues are both mathematics majors and Thanmaya is a computer science major.
"Working on forecasting the elections has combined three passions of mine – math, data, and impactful work – into one project,” says Rodrigues. “I am grateful for the learning opportunities and community involvement that this project has given me thus far."
“This is my second year mentoring an interdisciplinary undergraduate elections team at Purdue. The students have been supported by the Purdue Office of Undergraduate Research (OUR) Scholars program and the Purdue Engineering Undergraduate Research Office (EURO) Summer Undergraduate Research Fellowship (SURF) program,” says Volkening.
The group will be posting updated forecasts on their website until November 5 and have been doing so since early September. The team takes a mathematical modeling and data-scientific perspective on elections, and they stress the uncertainty in forecasts. They hit a slight delay back in September with President Joseph Biden dropping out of the election but have updated the site to reflect the new candidate.
“This year we have links on our main page to voter registration information to encourage voting, and the students have created an interactive ‘Swing the states!’ feature that allows viewers to interact with our model and incorporate their own hunches into our forecasts by clicking different swing states. One of our goals is to communicate concepts in math and data science accessibly on our site,” says Volkening.
"I really enjoy being a part of this project because I get to use the subject that I love to explore the fascinating and complicated topic of election forecasting,” says Cromp. “Being a part of this project has been highly rewarding and fun."
If you’d like to hear more about the group’s work, check out this episode of Superheroes of Science where the team is interviewed by K-12 Outreach coordinators Sarah Nern and Steven Smith from Purdue University’s Departments of Chemistry and Earth, Atmospheric, and Planetary Sciences.
Contributors:
Alexandria Volkening, assistant professor of mathematics at the Purdue University College of Science and courtesy appointment with the Weldon School of Biomedical Engineering
Joseph Cromp, undergraduate student from the Purdue University Department of Mathematics
Thanmaya Pattanashetty, undergraduate student from the Purdue University Department of Computer Science
Alexia Rodrigues undergraduate student from the Purdue University Department of Mathematics
Writer: Cheryl Pierce, Communications Specialist