Table 1.

Bias, variance, empirical variance and Type I error rate (α) of tests performed at the 5% signi cance level.

(δ, λ)	Estimator	Bias	Variance	Empirical Var	α
(0,0)	ACE	9 10-5	0.0023	0.0023	0.045
	CI	6 10-4	0.0025	0.0024	0.037
	G	8 10-4	0.00067	0.00072	0.066
	OLS	4 10-4	0.00041	0.00042	0.058
	NI	6 10-4	-	0.0010	-
(0,-2)	ACE	9 10-5	0.0023	0.0023	0.045
	CI	-0.024	0.14	0.11	0.066
	G	1.32	0.0056	0.0058	1.00
	OLS	2.40	0.0050	0.019	1.00
	NI	0.063	-	0.028	-
(1,0)	ACE	3 10-4	0.0013	0.0013	0.050
	CI	3 10-3	0.00059	0.00052	0.053
	G	1 10-4	0.00028	0.00029	0.054
	OLS	5 10-5	0.00023	0.00023	0.050
	NI	5 10-4	-	0.0011	-
(1,-2)	ACE	0.00029	0.0013	0.0013	0.050
	CI	0.12	0.016	0.016	0.24
	G	0.57	0.0062	0.0063	1.00
	OLS	1.33	0.0056	0.029	1.00
	NI	-0.30	-	0.035	-