Quarterly returns for four export portfolios. The first row gives the value of the coefficients. The second row gives the t-stat for the coefficients. The critical values for t-stat for DF = 17 are 2.8982 (1%), 2.1098 (5%) and 1.7396 (10%) for 1988-1992, and for DF = 18, 2.8784 (1%), 2.1009 (5%) and 1.7341 (10%). These are designated by ^*, ^ and ^* respectively.
Sample	Fuel Products		Manufactured Products		Agricultural Products		Minerals & Ores
Period	Intercept	Slope	Intercept	Slope	Intercept	Slope	Intercept	Slope
1988-1992	0.0265	0.7858	0.0042	0.9096	0.0155	0.1155	0.0021	0.6651
	0.9514	2.0239^*	1.7713	27.8383^***	0.6930	0.3702	0.1187	2.7127^**
1989-1993	0.0204	1.1504	0.0026	0.9038	0.0101	0.1754	0.0038	0.3032
	0.8095	3.0507^***	0.9921	23.0054^***	0.5003	0.5781	0.2068	1.0999
1990-1994	0.0082	1.2320	0.0035	0.9284	0.0214	0.2445	0.0150	0.2651
	0.3285	3.4970^***	1.3003	24.6511^***	1.0589	0.8561	0.8258	1.0327
1991-1995	−0.0018	0.9824	0.0024	0.9531	0.0110	0.5081	0.0215	0.0483
	−0.0921	3.3220^***	1.0079	26.6668^***	0.5004	1.5209	1.2093	0.1793
1992-1996	0.0259	0.7486	−0.0010	0.9966	0.0248	0.4773	0.0292	−0.0700
	1.6123	2.8412^**	−0.4357	25.8767^***	1.1688	1.3733	1.6921	−0.2472
1993-1997	0.0026	0.9271	−0.0007	0.9939	0.0185	0.6744	0.0320	−0.1639
	0.2005	4.6862^***	−0.3231	31.5451^***	0.8135	1.9262^*	1.6404	−0.5469
1994-1998	−0.0080	1.0021	0.0005	0.9949	0.0101	0.8563	0.0238	0.1621
	−0.5486	4.4041^***	0.2625	35.6435^***	0.3641	1.9901^*	1.2639	0.5536
1995-1999	0.0025	1.2186	−0.0006	1.0025	0.0045	0.9204	0.0142	0.1268
	0.1532	4.5051^***	−0.2985	31.2258^***	0.1627	1.9787^*	0.8090	0.4329
1996-2000	0.0151	1.2731	−0.0011	1.0158	0.0043	0.8459	0.0079	0.0049
	0.9204	4.3772^***	−0.5725	28.7913^***	0.1661	1.8583^*	0.4993	0.0175
1997-2001	−0.0048	1.4357	−0.0002	1.0014	−0.0036	0.8955	0.0036	0.0522
	−0.2917	4.6587^***	−0.1278	29.8860^***	−0.1507	2.0136^*	0.2463	0.1944
1998-2002	0.0022	1.6105	−0.0012	0.9839	0.0013	0.8238	0.0019	0.4478
	0.1484	6.0714^***	−0.6823	29.7929^***	0.0551	2.0015^*	0.1680	2.1838^**