Table 1.

Regression Estimates for the Initial and Final Regression-Discontinuity Models

Variable	Regression Coefficient	Standard Error	p
Initial model
Constant	0.511	0.051	<.001
Linear (Xi)	0.351	0.199	.078
Intervention effect (Ti)	−0.186	0.065	.004
Linear interaction (XiTi)	0.269	0.219	.220
Quadratic (Xi2)	−0.158	0.179	.378
Quadratic interaction (Xi2Ti)	0.138	0.183	.449
	R2=0.228
Final model
Constant	0.568	0.018	<.001
Linear (Xi)	0.549	0.025	<.001
Intervention effect (Ti)	−0.213	0.038	<.001
	R2=0.228

X_i is the pretest measure minus the cutoff for individual i; T_i is the treatment indicator (1 for treatment; 0 for control).