New Estimates of Over 500 Years of Historic GDP and Population Data. (with Christopher J. Fariss, Therese Anders, and Jonathan N. Markowitz). Journal of Conflict Resolution, 66:3 (April 2022). p. 553 - 591.

Preprint --- Appendix --- Replication materials

Gross domestic product (GDP), GDP per capita, and population are central to the study of politics and economics broadly, and conflict processes in particular. Despite the prominence of these variables in empirical research, existing data lack historical coverage and are assumed to be measured without error. We develop a latent variable modeling framework that expands data coverage (1500 AD–2018 AD) and, by making use of multiple indicators for each variable, provides a principled framework to estimate uncertainty for values for all country-year variables relative to one another. Expanded temporal coverage of estimates provides new insights about the relationship between development and democracy, conflict, repression, and health. We also demonstrate how to incorporate uncertainty in observational models. Results show that the relationship between repression and development is weaker than models that do not incorporate uncertainty suggest. Future extensions of the latent variable model can address other forms of systematic measurement error with new data, new measurement theory, or both.

Is the NPT Unravelling? Evidence from Text Analysis of Review Conference Statements. (with James Lo). Journal of Peace Research, 57:6 (December 2020), p. 740 - 751.

Preprint --- Appendix --- Replication materials

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is a landmark international treaty that is widely regarded as a cornerstone of the global nuclear non-proliferation regime. However, pessimists point to a growing divergence of preferences between nuclear weapons states and non-nuclear weapons states as a precursor to the impending ‘unraveling of this vital piece of international law’. In this article, we test for evidence of preference divergence using statements from NPT review conferences, which are manifestos presenting each country’s position on the NPT. We measure preferences on the NPT using Wordfish, a method that is frequently used to estimate ideological preferences from election manifestos. Our measure estimates the latent positions of state actors along a ‘non-proliferation vs. disarmament’ dimension, and shows little evidence of growing preference divergence between the nuclear weapons states and non-nuclear weapons states. Thus, a significant premise underlying more pessimistic assessments of the NPT appears to be in doubt.


Handling Missing and Incomplete Data. Forthcoming in Huddleston, R.Joseph, Thomas Jamieson, and Patrick James (Eds.), Handbook of Research Methods in International Relations. Cheltenham, UK: Edward Elgar Publishing.

Working Papers

Do Nuclear Weapons Matter in Near Crisis Situations? (with Patrick James).

De Jure Powersharing 1975-2019: Updating the Inclusion, Dispersion and Constraints Dataset. (with Alix Ziff, Ashley Abadeer, Jasmine Chu, Nicole Jao, Marie Zaragoza, and Benjamin A.T. Graham).

National Security, Regime Security, and WMD Proliferation Choices.

Measuring Arms: Introducing the Global Military Spending Dataset. (with Christopher J. Fariss, Jonathan N. Markowitz, and Gaea Morales).

Trade is the Weakest Form of Interdependence: Foreign Investment, Migration, and Conflict. (with Benjamin A.T. Graham).

Targeting Allies? Deterrence, Disarmament, and NGO Activism.

Measuring Geopolitical Competition. (with Jonathan N. Markowitz and Christopher J. Fariss).