# Two-Stage Difference-in-Differences Following Gardner (2021)

## Documentation for package ‘did2s’ version 1.2.1

- DESCRIPTION file.
- User guides, package vignettes and other documentation.
- Package NEWS.

## Help Pages

castle | Data from Cheng and Hoekstra (2013)
df_het | Simulated data with two treatment groups and heterogenous effects
df_hom | Simulated data with two treatment groups and homogenous effects
did2s | Calculate two-stage difference-in-differences following Gardner (2021)
event_study | Estimate event-study coefficients using TWFE and 5 proposed improvements.
gen_data | Generate TWFE data
get_honestdid_obj_did2s | get_honestdid_obj_did2s
honest_did_did2s | honest_did_did2s
plot_event_study | Estimate event-study coefficients using TWFE and 5 proposed improvements.
robust_solve_XtX | Robust solve for X'X beta = X'Y using QR decomposition