Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2} | {}

Parameter: λ13

Parameter: λ14

Parameter: λ23 Identified

Algebraic Equations:

σ122λ2312σ1311σ22λ2311σ23

Single Door Criterion:

{2} ⊥ {3,4} | {1}

Parameter: λ34 Identified

Algebraic Equations:

σ12σ13λ3412σ1411σ23λ3411σ24

Instrumental Variable:

2 | {1}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω13

Parameter: ω14

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33

Parameter: ω44

Total Effect of X1 on X3: λ12λ2313

Path-specific Effect of X1 on X3: λ12λ23 Identified

Algebraic Equations:

σ11σ122λ12λ23122σ13112σ22λ12λ2311σ12σ23

Total Effect of X1 on X4: λ12λ23λ3413λ3414

Path-specific Effect of X1 on X4: λ12λ23λ34 Identified

Algebraic Equations:

σ11σ122λ12λ23λ34122σ14112σ22λ12λ23λ3411σ12σ24

Path-specific Effect of X1 on X4: λ13λ34

Total Effect of X2 on X4: λ23λ34 Identified

Each Parameter Identified

Back Door Criterion:


{2} ⊥ {3,4} | {1}

Vanishing Ideal

Zero Vanishing Ideal