| 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 |