Table 5.

The Haussmann test for IIA assumption.

	Coefficients (b)	(B) Fe	(b)−(B) Difference	sqrt(diag(V_b−V_B)) S.E.
Frequency 3	.9953	.1786	.8167	.308
Frequency 5	1.2138	.393	.8207	.379
Duration 2	−.322	−2.214	1.89	.288
Duration 3	−2.922	−6.014	3.091	.371
Night time outage	−.300	−.332	.032	.328
chi2(6)	(b−B)'[(V_b−V_B)ˆ(−1)](b−B) 177.80
Prob > chi2	0.0000

Source: Author's computation, 2018.