Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2} | {}

Parameter: λ13 Identified

Algebraic Equations:

σ122λ1311σ22λ1313σ2212σ23

Single Door Criterion:

{1} ⊥ {3} | {2}

Parameter: λ14 Identified

Algebraic Equations:

σ12σ13λ1411σ23λ1414σ2313σ24

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: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33 Identified

Algebraic Equations:

132σ22+2σ12σ13σ2311σ232122σ3311σ22σ33122ω3311σ22ω33

Parameter: ω34 Identified

Algebraic Equations:

13σ14σ23132σ2412σ14σ3311σ24σ3312σ13σ3411σ23σ3412σ13ω3411σ23ω34

Parameter: ω44 Identified

Algebraic Equations:

σ11σ142σ232-2σ11σ13σ14σ23σ2411σ132σ242122σ142σ33+2σ11σ12σ14σ24σ33112σ242σ33+2σ122σ13σ14σ34-2σ11σ12σ14σ23σ34-2σ11σ12σ13σ24σ34+2σ112σ23σ24σ34122σ132σ44+2σ11σ12σ13σ23σ44112σ232σ44122σ132ω44-2σ11σ12σ13σ23ω44112σ232ω44

Total Effect of X1 on X3: λ12λ2313 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,3,4} | {}

Total Effect of X1 on X4: λ12λ23λ3413λ3414 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,3,4} | {}

Total Effect of X2 on X4: λ23λ34 Identified

Each Parameter Identified

Back Door Criterion:


{2} ⊥ {3,4} | {1}

Vanishing Ideal

Zero Vanishing Ideal