In the following simultaneous equation models,
Y1t - β10 - β12Y2t - β13Y3t - α11X1t = u1t - (1)
Y2t - β20 - β23Y3t - α21X1t - α22X2t = u2t - (2)
Y3t - β30 - β31Y1t - α31X1t - α32X2t = u3t - (3)
Y4t - β40 - β41Y1t - β42Y2t - α43X3t = u4t - (4)
Based on the rank condition, find the equation - (2) is ____.
1
Identified
2
Over identified
3
Unidentified
4
None of the above