nonabsdid - Visualize Heterogeneity-Robust Event Studies for Non-Absorbing
Treatments
Runs several heterogeneity-robust
difference-in-differences (DID) event-study estimators for
non-absorbing (i.e., treatment can switch on and off over time,
allowing treatment reversal) binary treatments through their
respective packages, harmonizes their output onto a common time
axis and tidy data structure, and overlays them in a single
'ggplot2' panel for visual comparison. Supported estimators
include those provided by 'DIDmultiplegtDYN', 'PanelMatch', and
'fect', with an optional naive two-way fixed-effects reference
series via 'fixest'. The underlying methods are respectively
described in Clement de Chaisemartin and Xavier
D'Haultfoeuille. "Difference-in-Differences Estimators of
Intertemporal Treatment Effects." The Review of Economics and
Statistics (2026) <doi:10.1162/rest_a_01414>, Kosuke Imai, In
Song Kim, and Erik H. Wang. "Matching methods for causal
inference with time‐series cross‐sectional data." American
Journal of Political Science 67.3 (2023)
<doi:10.1111/ajps.12685>, Licheng Liu, Ye Wang, and Yiqing Xu.
"A practical guide to counterfactual estimators for causal
inference with time‐series cross‐sectional data." American
Journal of Political Science 68.1 (2024)
<doi:10.1111/ajps.12723>, and Laurent R. Bergé, Kyle Butts, and
Grant McDermott. "Fast and user-friendly econometrics
estimations: The R package 'fixest'." arXiv preprint (2026)
<doi:10.48550/arXiv.2601.21749>. A single nabs_event_study()
wrapper runs any supported estimator with a common interface;
nabs_event_study_simple() provides a one-line front door for
quick exploratory runs; the S3 generic as_nabs_event_study()
coerces estimator output into a tidy stable schema; and
nabs_event_plot() overlays multiple methods on a single
'ggplot2' panel, with optional naive two-way fixed effects
drawn in a neutral color as a reference.
