T. Ryan Johnson

About Me

I received my Ph.D. in Political Science from Washington University in St. Louis in May 2026. I have been an Adjunct Instructor in the Department of Computer Science at Saint Louis University since 2024. In 2025 I was a Mathematical Statistician at the U.S. Census Bureau.

I combine large administrative datasets, GIS, and formal models of choice to study how institutions and markets shape what people do and believe. To measure those effects, I develop game theoretic and spatial methods to disentangle institutional influence from individual choice.

My research has appeared in Economica and the Journal of Theoretical Politics. Part of my dissertation was supported by the Weidenbaum Center on the Economy, Government, and Public Policy.

Research Interests

Political Economy: borders and territory, conflict, electoral institutions
Methodology: Bayesian machine learning, causal inference, formal theory, spatial statistics

Publications

bin Oslan, Afiq and T. Ryan Johnson (2026). “Spies in a barrel: When to reel in espionage.” Journal of Theoretical Politics 38 (2), 87–109.

PDF DOI
Johnson, T. Ryan and Dietrich Vollrath (2020). “The Role of Land in Temperate and Tropical Agriculture.” Economica 87 (348), 901–937.

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Working Papers

Gaussian Processes for Spatial Confounding
Gaussian Processes for Spatial Dependence
Kriging for Robust Standard Errors
Spurious Spatial Econometrics

Work in Progress

Estimating the Random Coefficients Logit with Voter Files
Flood Risk and Turnout
Sophisticated Voting in an Approval Primary

Teaching

Saint Louis University, Department of Computer Science

Databases (CSCI 4710/5710), Fall 2026
Introduction to Computer Science: Taming Big Data (CSCI 1070), Fall 2024
GitHub

Saint Louis University, Department of Earth and Atmospheric Sciences

Introduction to Geographic Information Systems (GIS 4010/5010), Fall 2024

Washington University in St. Louis, Department of Political Science

TA for PhD courses:
- Math Camp (Summer 2021, Summer 2022)
- Applied Statistical Programming (Spring 2022)
  GitHub
- Formal Models of Political Institution (Fall 2021)
- American Political Institutions (Fall 2021)
- Causal Inference (Spring 2021)
- Computational Social Science (Fall 2020)
- Theories of Individual and Collective Choice II (Spring 2020)
- Mathematical Modeling (Fall 2019)

Sam Houston State University, Department of Mathematics & Statistics

Developmental Mathematics II, Fall 2011–Spring 2013