Table 7. Two-Step Estimates of Intensity-of-Use Equation Part B Expenditures, Parameter Estimates, and Standard Errors.

Variable	Model 1		Model 2		Model 3		Model 4
	Mean	Standard Deviation	Mean	Standard Deviation	Mean	Standard Deviation	Mean	Standard Deviation
QMB enrollment	0.431	0.106	0.360	0.553	0.501	0.357	0.721	0.567
H	—	—	0.241	0.333	-0.043	0.217	-0.170	-0.343
Instrument Set	—	—	Percent of Medicaid population that is elderly		Percent of Medicaid population that is elderly, and its square		Percent of Medicaid population that is elderly, and number of QMB outreach programs (0-7)

NOTES: Other exogenous variables include those listed in Table 3. Standard errors are calculated by the procedure suggested by Greene (1981). The results for model 1 are the single-equation estimates reported in Table 3. QMB is qualified Medicare beneficiary.

SOURCE: Parente, S., and Evans, W., Project HOPE, Bethesda, MD, 1999.