Table 7: Maximum likelihood estimates of the common stochastic production in the frontier model.

Variable Name	Parameter	Coefficient	Standard Error	Z	P>|z|
In(X1)	β1	3.80	2.63	1.44	0.15
In(X2)	β2	1.78	1.99	0.89	0.37
In(X3)	β3	6.86	3.23	2.12	0.03
In(X4)	β4	0.59	1.73	0.34	0.74
In(X5)	Β5	5.81	2.04	2.85	0.00
In(X6)	Β6	4.99	2.68	1.86	0.06
In(X7)	Β7	2.74	14.30	0.19	0.85
In(X1)*In(X1)	Β8	0.19	0.16	1.22	0.22
In(X2)*In(X2)	Β9	0.20	0.07	2.93	0.00
In(X3)*In(X3)	Β10	0.04	0.29	0.13	0.90
In(X4)*In(X4)	Β11	0.21	0.08	2.72	0.01
In(X5)*In(X5)	Β12	0.14	0.08	1.71	0.09
In(X6)*In(X6)	Β13	-0.07	0.12	-0.60	0.55
In(X7)*In(X7)	Β14	-0.14	1.16	-0.12	0.90
In(X1)*In(X2)	Β15	0.20	0.20	1.00	0.32
In(X1)*In(X3)	Β16	-0.50	0.35	-1.44	0.15
In(X1)*In(X4)	Β17	-0.07	0.19	-0.36	0.72
In(X1)*In(X5)	Β18	0.25	0.18	1.44	0.15
In(X1)*In(X6)	Β19	-0.20	0.31	-0.66	0.51
In(X1)*In(X7)	Β20	-1.14	0.49	-2.31	0.02
In(X2)*In(X3)	Β21	-0.13	0.21	-0.61	0.54
In(X2)*In(X4)	Β22	0.09	0.09	0.96	0.34
In(X2)*In(X5)	Β23	-0.23	0.09	-2.57	0.01
In(X2)*In(X6)	Β24	-0.39	0.17	-2.28	0.02
In(X2)*In(X7)	Β25	-0.24	0.34	-0.71	0.48
In(X3)*In(X4)	Β26	0.03	0.28	0.10	0.92
In(X3)*In(X5)	Β27	-0.35	0.27	-1.26	0.21
In(X3)*In(X6)	Β28	0.09	0.37	0.24	0.81
In(X3)*In(X7)	Β29	-0.41	0.54	-0.75	0.45
In(X4)*In(X5)	Β30	-0.10	0.10	-1.07	0.29
In(X4)*In(X6)	Β31	0.01	0.18	0.06	0.95
In(X4)*In(X7)	Β32	-0.06	0.27	-0.21	0.83
In(X5)*In(X6)	Β33	0.41	0.14	2.94	0.00
In(X5)*In(X7)	Β34	0.68	0.34	2.02	0.04
In(X6)*In(X7)	Β35	1.21	0.41	2.96	0.00
Constant	Β0	28.17	41.35	0.68	0.50