Table 7.—Linear Trends in Dispersion and Bias in Revisions in the Quarterly Changes in GDP

	Dispersion						Bias
	Advance to preliminary	Preliminary to final	Advance to final	To third annual revision estimate from:			Advance to preliminary	Preliminary to final	Advance to final	To third annual revision estimate from:
				Advance	Preliminary	Final				Advance	Preliminary	Final
	Current-dollar estimates
Period beginning with 1978:
Slope coefficient	(-)	(-*)	(-)	(-)	(-)	(-)	(+)	(+*)	(+)	(+)	(+)	(+)
First-trend value	0.9	0.5	1.0	2.0	1.7	1.7	-0.3	-0.2	-0.5	-1.1	-0.7	-0.5
Last-trend value	.5	.3	.6	1.2	1.0	1.1	-.2	.2	0	-.2	0	-.1
Period beginning with 1982:
Slope coefficient	(+)	(-)	(-)	(-)	(-)	(-)	(-)	(+)	(-)	(-)	(-)	(-)
First-trend value	.5	.4	.9	2.4	2.7	2.6	.4	-.1	.3	.6	-.1	0
Last-trend value	.5	.3	.7	1.6	1.6	1.6	-.2	.1	-.1	-.2	-.2	-.2
	Constant-dollar estimates
Period beginning with 1978:
Slope coefficient	(-)	(-*)	(-)	(-)	(+)	(+)	(+)	(+*)	(+)	(+)	(+)	(+)
First-trend value	.6	.5	.8	1.7	1.4	1.4	-.2	-.3	-.5	-.9	-.7	-.4
Last-trend value	.5	.2	.5	1.4	1.5	1.7	-.1	.2	.1	0	.1	-.1
Period beginning with 1982:
Slope coefficient	(-)	(-)	(-)	(-)	(-)	(-)	(-)	(+)	(+)	(+)	(+)	(+)
First-trend value	.5	.5	.9	1.9	1.9	1.8	.1	-.1	-.1	-1.2	-1.3	-1.2
Last-trend value	.5	.3	.6	1.6	1.6	1.7	-.1	.1	0	-.5	-.4	-.5

* Significant at the 5-percent confidence level.

1. Calculated from quarterly percentage changes at seasonally adjusted annual rates.