Table 5.

Regression models for total medical expenditures

	Bivariate sample selection				IV bivariate sample selectiona
	Participation eq.		Outcome eq.		Participation eq.		Outcome eq.
Variable	Coeff	t-value	Coeff	t-value	Coeff	t-value	Coeff	t-value
Health index	−0.03	−0.74	−0.14	−3.68	−0.06	−0.46	0.01	0.08
Private insurance	0.24	1.23	0.01	0.02	0.27	1.62	0.11	0.41
Log wage	0.06	0.66	0.13	1.43	0.07	0.69	0.07	0.55
a = (Age − 50)/10	0.23	3.64	0.21	1.94	0.23	2.73	0.34	2.90
a2	0.00	−0.13	0.03	0.60	0.00	0.11	0.01	0.17
Secondary education	0.12	1.02	−0.04	−0.19	0.15	1.18	−0.10	−0.44
Tertiary education	0.20	1.29	0.06	0.27	0.26	1.35	−0.08	−0.26
Wife’s education	0.00	0.03	0.01	0.25	0.00	0.02	0.00	−0.12
Black	−0.05	−0.40	−0.42	−2.83	−0.07	−0.60	−0.38	−2.16
Other race	0.03	0.21	−0.50	−2.47	0.01	0.06	−0.51	−2.50
Married	−0.05	−0.19	−0.26	−0.54	−0.06	−0.19	−0.16	−0.33
Suburban	−0.01	−0.14	−0.01	−0.06	−0.01	−0.07	−0.02	−0.19
Rural	0.00	0.02	−0.02	−0.16	0.01	0.12	−0.01	−0.09
Household size	−0.01	−0.19	−0.10	−1.89	−0.01	−0.16	−0.11	−2.25
Constant	0.75	2.03	7.99	12.59	0.83	1.58	7.25	11.40
N	2,821		2,202 – 2,270b		2,821		2,202 – 2,270b

^aThe first stage F statistic for the IV regression is 56.3.

^bThe number of positive observations varies between imputed data sets.