Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2} | {}

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 Identified

Algebraic Equations:

σ11σ13σ2211σ12σ23122ω1311σ22ω13

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33 Identified

Algebraic Equations:

122σ132σ22+2σ123σ13σ23-2σ11σ122σ232112σ22σ232124σ33+2σ11σ122σ22σ33112σ222σ33124ω33-2σ11σ122σ22ω33112σ222ω33

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 Identified

Each Parameter Identified

Total Effect of X1 on X4: λ12λ23λ3412λ24 Identified

Each Parameter Identified

Total Effect of X2 on X4: λ23λ3424 Identified

Each Parameter Identified

Back Door Criterion:


{2} ⊥ {3,4} | {1}

Vanishing Ideal

Zero Vanishing Ideal