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: λ24 Identified

Algebraic Equations:

σ13σ22λ2412σ23λ2414σ2313σ24

Parameter: λ34 Identified

Algebraic Equations:

σ13σ22λ3414σ2212σ23λ3412σ24

Instrumental Variable:

1 | {2}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω13

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33

Parameter: ω34 Identified

Algebraic Equations:

14σ23213σ23σ2414σ22σ3312σ24σ3313σ22σ3412σ23σ3413σ22ω3412σ23ω34

Parameter: ω44 Identified

Algebraic Equations:

σ142σ22σ232-2σ13σ14σ22σ23σ24132σ22σ242142σ222σ33+2σ12σ14σ22σ24σ33122σ242σ33+2σ13σ14σ222σ34-2σ12σ14σ22σ23σ34-2σ12σ13σ22σ24σ34+2σ122σ23σ24σ34132σ222σ44+2σ12σ13σ22σ23σ44122σ232σ44132σ222ω44-2σ12σ13σ22σ23ω44122σ232ω44

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: λ12λ23λ3412λ2413λ34

Path-specific Effect of X1 on X4: λ12λ23λ34 Identified

Algebraic Equations:

σ11σ122σ13σ22λ12λ23λ34122σ13σ14σ22112σ13σ222λ12λ23λ3411σ123σ23λ12λ23λ34112σ12σ22σ23λ12λ23λ3411σ12σ14σ22σ23123σ13σ2411σ122σ23σ24

Path-specific Effect of X1 on X4: λ12λ24 Identified

Algebraic Equations:

σ11σ13σ22λ12λ2411σ12σ23λ12λ2412σ14σ2312σ13σ24

Path-specific Effect of X1 on X4: λ13λ34

Total Effect of X2 on X4: λ23λ3424 Identified

Each Parameter Identified

Back Door Criterion:


{2} ⊥ {3,4} | {1}

Vanishing Ideal

Zero Vanishing Ideal