Dahyun Choi

Hello! I'm a Postdoctoral Fellow at the Kellogg School of Management at Northwestern University. My research asks how information shapes public policy: who produces the knowledge that reaches government, how interests and ideology color its application, and which evidence ultimately prevails. I study these questions across regulatory agencies, firms, interest groups, and Congress, in environmental regulation, antitrust, trade, and science policy.

A second strand asks what happens when the machinery of policymaking is itself automated: where generative AI has been adopted inside government, and how courts, elections, and legislatures govern its use. Across both strands I develop computational and statistical methods for measuring political and organizational text, including tools for research design and for valid inference when the measurement itself comes from a machine.

I received my Ph.D. in Politics from Princeton University in 2026, with a Graduate Certificate in Statistics and Machine Learning.

Selected Publications

View All →
Partisan Bias and the Resilience of High-Impact ScienceAmerican Journal of Political Science, accepted.
How do partisan bias and scholarly impact within academic communities jointly shape the use of evidence in regulatory policymaking? I investigate this question using a novel dataset of 16,783 peer-reviewed studies evaluated by the Environmental Protection Agency for the Integrated Science Assessments (ISA), which inform the National Ambient Air Quality Standards. I find that Democratic administrations are 15.4% more likely to cite pro-regulatory studies, while Republican administrations are 17.5% less likely to do so. These effects correspond to a two-standard-deviation change in study impact measures. Yet partisan bias is moderated by evidentiary impact: high-impact studies are cited consistently across administrations, while lower-impact studies are less penalized when aligned with an administration's policy agenda. Evidence on participant selection in the ISA process suggests a plausible mechanism underlying this pattern. Together, the findings suggest that while science retains epistemic authority, its application is shaped by political context within the administrative state.
How Much Data Is Enough? A Design-aware Approach to Empirical Sample ComplexityWith Perry Carter. American Journal of Political Science, accepted.
How much data is needed to ensure that a model performs reliably on new, unseen data? Despite its central importance to empirical research design, sample size decisions are often made heuristically—guided more by resource constraints than by principled diagnostics. Existing tools like power analysis and cross-validation offer limited insight into how predictive performance scales with sample size. We introduce a design-aware, empirical framework for estimating sample complexity bounds tailored to applied settings. By fitting smooth extrapolation functions to model performance from resampled pilot data, our method estimates the sample size needed to achieve researcher-specified generalization guarantees. Through applications to supervised learning tasks involving extensive human-annotated data, we show that generalization often stabilizes with as little as 10% of typical labeling costs. This approach provides a statistically grounded, interpretable diagnostic for generalization performance and a practical tool for political scientists designing data-intensive studies under resource constraints or design uncertainty.
Fine-tuned Large Language Models Can Replicate Expert Coding Better than Trained CodersWith Brandon Stewart and Denis Peskoff. Political Science Research and Methods, forthcoming.
Understanding the political process in the United States requires examining how information is provided to politicians and the general public. While existing studies point to interest groups as strategic information providers, studying this aspect empirically has been challenging due to the need for expert-level annotation in measurement. We make two contributions. First, we demonstrate that fine-tuned large language models (LLMs) can replicate expert-level annotation in a specialized area above the accuracy of lightly-trained workers, crowd-workers, and zero-shot LLMs. Second, we quantify two types of interest group signals that are difficult to separate empirically using other means: 1) informative signals that help agents improve political decisions, and 2) associative signals that influence preference formation but lack direct relevance to the substantive topic of interest. We demonstrate the utility of this approach using two applications where our classifier generalizes out of distribution. This study shows methodologically the applicability of large language models for complex expert-driven measurement tasks but also shows substantively that interest groups strategically tailor the composition of signals under different institutional settings.
Why Interest Groups With Divergent Goals Collaborate: Evidence From Climate RegulationEconomics & Politics, 2026.
Why do interest groups with contrasting interests and policy goals work together? I present a theory of collaborative policy production and show that interest groups can achieve higher policy gains through collaboration, even though their ideal policy goals may diverge significantly. To test theoretical results, I introduce original measurement strategies that reveal systematic patterns in which firms and environmental groups invest in joint efforts to improve fine-grained details of policy to achieve greenhouse gas emissions targets. The analysis, using public comments spanning 2010-2020, demonstrates that comments written jointly by environmental groups and firms contain more information that can contribute to the quality of policy implementation than individual efforts alone, despite compromises on policy preferences. These findings highlight the hidden dynamics of regulatory politics, wherein divergent political goals are reconciled for high-quality policy implementation.

Publications

Partisan Bias and the Resilience of High-Impact ScienceAmerican Journal of Political Science, accepted.
How do partisan bias and scholarly impact within academic communities jointly shape the use of evidence in regulatory policymaking? I investigate this question using a novel dataset of 16,783 peer-reviewed studies evaluated by the Environmental Protection Agency for the Integrated Science Assessments (ISA), which inform the National Ambient Air Quality Standards. I find that Democratic administrations are 15.4% more likely to cite pro-regulatory studies, while Republican administrations are 17.5% less likely to do so. These effects correspond to a two-standard-deviation change in study impact measures. Yet partisan bias is moderated by evidentiary impact: high-impact studies are cited consistently across administrations, while lower-impact studies are less penalized when aligned with an administration's policy agenda. Evidence on participant selection in the ISA process suggests a plausible mechanism underlying this pattern. Together, the findings suggest that while science retains epistemic authority, its application is shaped by political context within the administrative state.
Evidence Use in PolicymakingBureaucracy & RegulationText as Data & LLM MeasurementEnvironmental Regulation
Fine-tuned Large Language Models Can Replicate Expert Coding Better than Trained Coders: A Study on Informative Signals Sent by Interest GroupsWith Brandon Stewart and Denis Peskoff. Political Science Research and Methods, forthcoming.
Understanding the political process in the United States requires examining how information is provided to politicians and the general public. While existing studies point to interest groups as strategic information providers, studying this aspect empirically has been challenging due to the need for expert-level annotation in measurement. We make two contributions. First, we demonstrate that fine-tuned large language models (LLMs) can replicate expert-level annotation in a specialized area above the accuracy of lightly-trained workers, crowd-workers, and zero-shot LLMs. Second, we quantify two types of interest group signals that are difficult to separate empirically using other means: 1) informative signals that help agents improve political decisions, and 2) associative signals that influence preference formation but lack direct relevance to the substantive topic of interest. We demonstrate the utility of this approach using two applications where our classifier generalizes out of distribution. This study shows methodologically the applicability of large language models for complex expert-driven measurement tasks but also shows substantively that interest groups strategically tailor the composition of signals under different institutional settings.
Interest Groups & Informational LobbyingFirms & Nonmarket StrategyText as Data & LLM MeasurementMeasurement Error & Predicted VariablesTrade Policy
Why Interest Groups With Divergent Goals Collaborate: Evidence From Climate RegulationEconomics & Politics, 2026, 38: 46–61.
Why do interest groups with contrasting interests and policy goals work together? I present a theory of collaborative policy production and show that interest groups can achieve higher policy gains through collaboration, even though their ideal policy goals may diverge significantly. To test theoretical results, I introduce original measurement strategies that reveal systematic patterns in which firms and environmental groups invest in joint efforts to improve fine-grained details of policy to achieve greenhouse gas emissions targets. The analysis, using public comments spanning 2010-2020, demonstrates that comments written jointly by environmental groups and firms contain more information that can contribute to the quality of policy implementation than individual efforts alone, despite compromises on policy preferences. These findings highlight the hidden dynamics of regulatory politics, wherein divergent political goals are reconciled for high-quality policy implementation.
Firms & Nonmarket StrategyInterest Groups & Informational LobbyingFormal TheoryText as Data & LLM MeasurementEnvironmental Regulation
How Much Data Is Enough? A Design-aware Approach to Empirical Sample ComplexityWith Perry Carter. American Journal of Political Science, accepted.
How much data is needed to ensure that a model performs reliably on new, unseen data? Despite its central importance to empirical research design, sample size decisions are often made heuristically—guided more by resource constraints than by principled diagnostics. Existing tools like power analysis and cross-validation offer limited insight into how predictive performance scales with sample size. We introduce a design-aware, empirical framework for estimating sample complexity bounds tailored to applied settings. By fitting smooth extrapolation functions to model performance from resampled pilot data, our method estimates the sample size needed to achieve researcher-specified generalization guarantees. Through applications to supervised learning tasks involving extensive human-annotated data, we show that generalization often stabilizes with as little as 10% of typical labeling costs. This approach provides a statistically grounded, interpretable diagnostic for generalization performance and a practical tool for political scientists designing data-intensive studies under resource constraints or design uncertainty.
Measurement Error & Predicted VariablesResearch Design & Valid InferenceText as Data & LLM Measurement

Working Papers & Works in Progress

Politics of Academic Experts: Evidence from Antitrust LawsWith Nolan McCarty.
We investigate how government regulators use academic research as a function of scholars' political leanings and connections. We use three text-based measures to score each paper's slant on a latent dimension that captures the spectrum from the Chicago School to that of the neo-Brandeisians. In an author-by-paper dyad design, individual ideology scores robustly predict Chicago slant across all three measures. We do not find robust evidence connecting slant to institutional affiliation, however. With our measures, we model how different presidential administrations cite scholarship in their policy documents. We find that Democratic administrations cite antitrust scholarship roughly 1.47× more often. Furthermore, our analysis shows that Chicago-slanted scholarship is cited relatively more under Republican administrations, especially in the Department of Justice. Finally, we find that the political use of expertise is related to the content of the documents, not scholars' political preferences or connections.
Evidence Use in PolicymakingFirms & Nonmarket StrategyBureaucracy & RegulationAntitrust & Competition Policy
Artificial Intelligence and the Evidentiary Basis of PolicymakingWith Zander Furnas and Dashun Wang.
Evidence Use in PolicymakingInterest Groups & Informational LobbyingAlgorithmic GovernanceScience & Innovation Policy
Democratic AI-tocracy
Firms & Nonmarket StrategyPolitics of Technological ChangeElections & AccountabilityAI & Technology Policy
Detecting AI-Generated Language in Policy DocumentsWith Zander Furnas, Yifan Qian, Zhe Wen, and Dashun Wang.
Algorithmic GovernanceText as Data & LLM MeasurementBureaucracy & RegulationAI & Technology Policy
When the State Hands the Red Pen to a Machine
Algorithmic GovernanceBureaucracy & RegulationElections & AccountabilityAI & Technology Policy
Innovation by Design: How Legislative Institutions Shape the Direction of Federal R&D
Legislative InstitutionsPolitics of Technological ChangeScience & Innovation Policy
Decay, Renewal, and the Dynamics of the Presidential Party SystemWith Charles Cameron.
Why does neither party dominate American presidential elections permanently? We present the first direct estimates of the major party restoring forces long suspected but never formally identified. We model each party as a "restless bandit" whose performance stochastically decays and renews, and derive the optimal voting rule for a rational electorate. The resulting two-parameter system yields a three-state Markov chain. When decay and renewal rates sum to one, elections become exactly independent, because four years of stochastic evolution erase each party's initial condition. Using annual indicators of presidential performance from 1865 to 2024, we estimate an annual decay rate of 0.48 and a renewal rate of 0.43, placing the system near this knife-edge. The model fits observed run lengths and switching patterns. Rolling-window estimates point to a possible decline in the renewal-to-decay ratio over the twentieth century.
Elections & AccountabilityLegislative InstitutionsFormal Theory
Patrons, Citizens, and the Locus of Organizational BiasWith Charles Cameron.
Why is organized political voice distributed unevenly across citizens' positions and why is the weaker side of a cleavage, when organized at all, so often sustained by a single patron? We model a policy domain as a free-entry game: engaged citizens choose whether to join a group, founders whether and where to enter. Citizen funding alone partitions the engaged public into equal-mass niches, so organized voice tracks the density of engaged opinion and falls silent where it is thin. Committed patrons reshape this field, sustaining groups where citizens cannot, so the field can be biased even when the public is symmetric—the bias tracing to patron supply's skew, not citizen mobilization. This transmission is non-proportional: skew within the citizen-generated zone only relocates voice among already-represented positions, while skew beyond it becomes bias. Organizational bias is thus patron supply filtered through the citizen-made silent zone—largest where citizen demand is thinnest.
Firms & Nonmarket StrategyInterest Groups & Informational LobbyingFormal Theory
Valid Inference with Noisy AI-Text Detectors
Federal agencies in the United States gather information from the public through notice-and-comment rulemaking, and political scientists have long used those comments to study who participates and how agencies respond. Agencies are now sorting comments with machine classifiers, by topic, by position, and by whether a comment was written with a language model. This letter asks what such a label can be trusted to mean. The answer depends less on how accurate the classifier is than on how rare the category is. If machine-written comments are two percent of a docket, a classifier that mislabels only five percent of human-written comments is still wrong about three quarters of what it flags, and the objections an agency must answer are often raised by only a handful of commenters. For machine-written text, comments filed before language models were available show how often a detector falsely flags human writing. I show what that alone can support: claims about how much machine-written commenting has grown over time, but not claims about how much of any one docket it makes up, which require assuming the detector never misses a case. A small change in the detector's false-alarm rate can also be mistaken for a trend.
Measurement Error & Predicted VariablesResearch Design & Valid InferenceText as Data & LLM MeasurementBureaucracy & RegulationAlgorithmic Governance
Sample Complexity for Open-Ended Survey ResponsesWith Perry Carter and Narrelle Gilchrist.
Measurement Error & Predicted VariablesResearch Design & Valid InferenceText as Data & LLM Measurement

Software

scR
scR is an R package developed by Carter & Choi (2025) designed to help researchers determine how much data is needed for reliable generalization. It provides a design-aware empirical framework that estimates sample complexity using smooth extrapolation of model performance from pilot data. Additionally, scR offers theoretical guidance by calculating Vapnik-Chervonenkis Dimension (VCD). This interpretable diagnostic is particularly helpful for empirical researchers designing data-intensive studies under resource constraints or uncertainty. For more details, see Carter & Choi (2025), "How Much Data Is Enough? A Design-aware Approach to Empirical Sample Complexity" (doi:10.31219/osf.io/evrcj_v2).

Available on CRAN · with Perry Carter

Database

A Database of United States Federal Regulatory HistoriesComing soon.