Model errors in tree biomass estimates computed with an approximation to a missing covariance matrix

Table 5 Actual, refitted, and recovered variances of regression coefficients in Eqs. 1–7 in Table 8

Eq #	Actual	Refitted	Recovered	Recovered (robust)	P ₁ _×100	P ₂ _×100	P ₃ _×100
1	(0.04, 0.01)	(0.08, 0.01)	(0.07, 0.01)	(0.10, 0.02)	56	74	49
2	(0.55, 0.42, 0.020)	(2.64, 1.39, 0.044)	(2.36, 1.25, 0.039)	(2.88, 1.52, 0.048)	0.2	0.1	0.1
3	(0.27, 0.048)	(0.29, 0.041)	(0.26, 0.039)	(0.35, 0.053)	99	98	96
4	(0.084, 0.017)	(0.33, 0.049)	(0.29, 0.043)	(0.37, 0.06)	2	5	1
5	n.a.	(0.32, 7.1)10⁻³	(0.20, 9.4)10⁻³	(0.23, 10.6)10⁻³	n.a.	n.a.	n.a.
6	n.a.	(0.61, 4.7)10⁻¹	(0.42, 32.2)10⁻²	(0.12, 9.0)10⁻¹	n.a.	n.a.	n.a.
7	n.a.	(0.98, 16.8)10⁻³	(0.29, 19.4)10⁻³	(0.74, 29.4)10⁻³	n.a.	n.a.	n.a.

Actual covariance matrices are based on sample sizes listed in Table 8. P _i (i = 1, 2, 3) is the probability under H ₀ of: (1) actual = refitted; (2) actual = recovered; (3) actual = robust.

ISSN: 1750-0680