Parameter: λ12

Parameter: λ14

Parameter: λ23 Identified

Algebraic Equations:

σ12λ2313

Instrumental Variable:

1 | {}

Parameter: λ34

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω12

Parameter: ω14

Parameter: ω22

Parameter: ω23 Identified

Algebraic Equations:

σ13σ2212σ2312ω23

Parameter: ω33 Identified

Algebraic Equations:

132σ22+2σ12σ13σ23122σ33122ω33

Parameter: ω34

Parameter: ω44

Total Effect of X1 on X3: λ12λ23

Total Effect of X1 on X4: λ12λ23λ3414

Path-specific Effect of X1 on X4: λ12λ23λ34

Total Effect of X2 on X4: λ23λ34

Vanishing Ideal

Zero Vanishing Ideal