| • | I : W1i = Ii + eij, | W2i = 0, and ; |
| • | II : W1i = Ii + Sitij + eij, | W2i = 0, and ; |
| • | III : W1i = Ii + Sitij + eij, | W2i = 0; |
| • | IV : W1i = Ii + Sitij + eij, | W2i = γ1Ii; |
| • | V : W1i = Ii + Sitij + eij, | W2i = γ1Ii + γ2Si; |
| • | VI : W1i = Ii + Sitij + eij, | W2i = γ1Ii + γ3 log(Vi); |
| • | VII : W1i = Ii + Sitij + eij, | W2i = γ1Ii + γ2Si + γ3 log(Vi); |