Table 6.

Regression models for nights spent in a hospital

					Hurdle model
	Poisson		Negative binomial		Probit		Zero-Truncated Negative Binomial		IV Poissona
Variable	Coeff	t-value	Coeff	t-value	Coeff	t-value	Coeff	t-value	Coeff	t-value
Health index	−0.44	−4.03	−0.34	−4.72	−0.15	−6.28	−0.15	−1.94	−0.16	−0.43
Private insurance	−1.29	−3.55	−0.97	−2.79	−0.38	−3.10	−0.60	−1.79	−1.28	−3.34
Log wage	−0.08	−0.48	0.17	0.72	−0.06	−0.86	0.26	1.04	−0.19	−0.88
a = (Age − 50)/10	0.25	1.82	0.45	2.93	0.20	3.72	−0.08	−0.44	0.36	1.93
a2	−0.02	−0.25	−0.02	−0.23	0.03	1.14	−0.12	−1.30	−0.04	−0.50
Secondary education	0.29	0.93	−0.40	−0.88	0.11	1.01	−0.15	−0.43	0.13	0.35
Tertiary education	0.69	1.25	−0.52	−1.09	0.14	1.01	−0.11	−0.28	0.37	0.66
Wife’s education	−0.08	−1.89	−0.12	−2.01	−0.02	−1.02	−0.09	−1.12	−0.10	−1.93
Black	0.23	0.97	0.11	0.47	0.07	0.92	0.02	0.09	0.36	1.11
Other race	−0.33	−0.69	0.44	0.87	0.09	0.70	−0.09	−0.16	−0.33	−0.66
Married	0.02	0.03	0.51	0.54	−0.02	−0.09	0.43	0.38	0.20	0.28
Suburban	−0.25	−1.03	−0.03	−0.12	0.01	0.16	−0.18	−0.63	−0.26	−1.08
Rural	0.23	0.62	0.52	1.69	0.11	1.11	0.18	0.54	0.24	0.65
Household size	0.13	1.25	0.11	1.35	0.04	1.42	0.05	0.70	0.12	1.13
Constant	2.73	4.01	2.11	2.72	−0.20	−0.76	1.78	1.86	1.85	1.21
N	4,841		4,841		4,841		282		4,841

^aThe first stage F statistic for the IV regression is 87.5.