Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2} | {}

Parameter: λ23

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: ω23

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: λ12λ23

Total Effect of X1 on X4: λ12λ23λ3412λ24

Path-specific Effect of X1 on X4: λ12λ23λ34

Path-specific Effect of X1 on X4: λ12λ24 Identified

Algebraic Equations:

σ11σ13σ22λ12λ2411σ12σ23λ12λ2412σ14σ2312σ13σ24

Total Effect of X2 on X4: λ23λ3424

Path-specific Effect of X2 on X4: λ23λ34

Vanishing Ideal

Zero Vanishing Ideal