rdrobust estimates a regression discontinuity effect at a threshold using local linear or local polynomial regression. It favors explicit, interpretable formulas over opaque machine-learning models. section 11.2.5
A practical workflow uses the package alongside exploratory and sensitivity checks:
- Plot the discontinuity with rdplot before estimating the effect. section 11.2.5
- Run rdrobust(Y, time_points) or its R equivalent to obtain an estimated effect and confidence interval. section 11.2.5
- Treat the time window and interval carefully: a reported estimate of 770.05 had a confidence interval from −11.42 to 1551.52. section 11.2.5
A time-based discontinuity
For an outcome Y measured around an event time T, rdrobust estimates the jump at T. Comparing alternative time windows shows why a seemingly better interval can reflect choosing a window with knowledge of the synthetic answer. section 11.2.5
Listing 11.10 (R) Nonlinear estimation with the rdrobust function.
summary(rdrobust(Y, time_points))
Inspect the R call and returned summary for nonlinear estimation with rdrobust. section 11.2.5
