Research

School Shootings and the Strategic Contributions of Gun Policy PACs in US House Elections

Eric A. Baldwin, Takuma Iwasaki (co-first author), and John J. Donohue.
Proceedings of the National Academy of Sciences, 123(9): e2514343123, 2026.

Paper · Replication Package · Op-ed in Time and Newsweek

Selected as runner-up for the George L. Priest Prize in Law and Economics, American Law and Economics Association, 2026.

A Gun with Two Addresses: Firearm Diversion and the Good-Neighbor Principle

Takuma Iwasaki (sole author).
Florida State University Law Review, forthcoming.

Source Independence among Directors

Takuma Iwasaki (sole author).
Stanford Journal of Law, Economics & Business, forthcoming.

The Price of Political Ties: Reputational Risk and the Strategic Divestment of Corporate PACs

Eric A. Baldwin, Takuma Iwasaki (co-first author), John J. Donohue, and Charlie Grabois.
National Bureau of Economic Research, No. w35494, 2026.

Paper

Loaded Chambers: Organized Interests, Public Opinion, and Policy Responsiveness in the American States

Takuma Iwasaki (co-first author), Eric A. Baldwin, John J. Donohue, and Tai Markman.
National Bureau of Economic Research, No. w34970, 2026.

Paper

How to Stabilize Corporate DEI Amid Backlash? Caremark and International Soft Law

Takuma Iwasaki (first author) and Masaki Fujita, 2026.

Paper

nonabsdid

CRAN R package for visualizing and comparing staggered DID event-study estimates under non-absorbing treatment.

Github

cfcompare

R package for implementing the TROP (triply robust panel) estimator and comparing it with other ATT estimators.

Github

ssBartik

R package for streamlining shift-share (Bartik) IV analysis.

Github