Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2} | {}

Parameter: λ13

Parameter: λ23 Identified

Algebraic Equations:

σ122λ2312σ1311σ22λ2311σ23

Single Door Criterion:

{2} ⊥ {3} | {1}

Parameter: λ34 Identified

Algebraic Equations:

σ13λ3414

Instrumental Variable:

1 | {}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω13

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω24 Identified

Algebraic Equations:

σ14σ2313σ2413ω24

Parameter: ω33

Parameter: ω34 Identified

Algebraic Equations:

12σ13σ14σ2311σ14σ23212σ132σ2411σ13σ23σ24122σ14σ3311σ14σ22σ33122σ13σ3411σ13σ22σ34122σ13ω3411σ13σ22ω34

Parameter: ω44 Identified

Algebraic Equations:

142σ33+2σ13σ14σ34132σ44132ω44

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: λ12λ23λ3413λ34

Path-specific Effect of X1 on X4: λ12λ23λ34 Identified

Algebraic Equations:

σ11σ122σ13λ12λ23λ34122σ13σ14112σ13σ22λ12λ23λ3411σ12σ14σ23

Path-specific Effect of X1 on X4: λ13λ34

Total Effect of X2 on X4: λ23λ34 Identified

Each Parameter Identified

Vanishing Ideal

Zero Vanishing Ideal