Parameter: λ13 Identified

Algebraic Equations:

σ122λ1311σ22λ1313σ2212σ23

Single Door Criterion:

{1} ⊥ {3} | {2}

Parameter: λ23 Identified

Algebraic Equations:

σ122λ2312σ1311σ22λ2311σ23

Single Door Criterion:

{2} ⊥ {3} | {1}

Parameter: λ34 Identified

Algebraic Equations:

σ23λ3424

Instrumental Variable:

2 | {}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω12 Identified

Algebraic Equations:

1212

Parameter: ω14 Identified

Algebraic Equations:

14σ2313σ2423ω14

Parameter: ω22 Identified

Algebraic Equations:

2222

Parameter: ω33 Identified

Algebraic Equations:

132σ22+2σ12σ13σ2311σ232122σ3311σ22σ33122ω3311σ22ω33

Parameter: ω34 Identified

Algebraic Equations:

13σ14σ22σ2312σ14σ232132σ22σ2412σ13σ23σ24122σ24σ3311σ22σ24σ33122σ23σ3411σ22σ23σ34122σ23ω3411σ22σ23ω34

Parameter: ω44 Identified

Algebraic Equations:

242σ33+2σ23σ24σ34232σ44232ω44

Total Effect of X1 on X4: λ13λ34 Identified

Each Parameter Identified

Total Effect of X2 on X4: λ23λ34 Identified

Each Parameter Identified

Vanishing Ideal

Zero Vanishing Ideal