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

Parameter: λ23 Identified

Algebraic Equations:

σ122λ2312σ1311σ22λ2311σ23

Single Door Criterion:

{2} ⊥ {3,4} | {1}

Parameter: λ34 Identified

Algebraic Equations:

σ13σ23λ3413σ2412σ33λ3412σ34,
σ132λ3413σ1411σ33λ3411σ34,
σ12σ13λ3412σ1411σ23λ3411σ24,
σ12σ14σ2311σ232λ3412σ13σ2411σ23σ24122σ33λ34122σ34

Single Door Criterion:

{3} ⊥ {4} | {1}
{3} ⊥ {4} | {1,2}

Instrumental Variable:

2 | {1}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω14

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33 Identified

Algebraic Equations:

132σ22+2σ12σ13σ2311σ232122σ3311σ22σ33122ω3311σ22ω33

Parameter: ω44

Total Effect of X1 on X3: λ12λ2313 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,3} | {}

Total Effect of X1 on X4: λ12λ23λ3413λ3414

Path-specific Effect of X1 on X4: λ12λ23λ34 Identified

Algebraic Equations:

σ11σ122λ12λ23λ34122σ14112σ22λ12λ23λ3411σ12σ24

Path-specific Effect of X1 on X4: λ13λ34 Identified

Algebraic Equations:

σ122σ13σ23λ13λ3411σ13σ22σ23λ13λ34132σ22σ2412σ13σ23σ24123σ33λ13λ3411σ12σ22σ33λ13λ3412σ13σ22σ34122σ23σ34,
σ122σ132λ13λ3411σ132σ22λ13λ34132σ14σ2212σ132σ2411σ122σ33λ13λ34122σ14σ33112σ22σ33λ13λ3411σ12σ24σ33122σ13σ3411σ13σ22σ34,
σ123σ13λ13λ3411σ12σ13σ22λ13λ3412σ13σ14σ2211σ122σ23λ13λ34122σ14σ23112σ22σ23λ13λ3411σ13σ22σ2411σ12σ23σ24,
σ11σ122σ232λ13λ34122σ14σ232112σ22σ232λ13λ34122σ13σ23σ2411σ13σ22σ23σ2411σ12σ232σ24124σ33λ13λ3411σ122σ22σ33λ13λ34122σ14σ22σ3311σ12σ22σ24σ33123σ23σ3411σ12σ22σ23σ34

Total Effect of X2 on X4: λ23λ34 Identified

Each Parameter Identified

Back Door Criterion:


{2} ⊥ {3,4} | {1}

Vanishing Ideal


Constraint Set:

σ13σ14σ23132σ2412σ14σ3311σ24σ3312σ13σ3411σ23σ34

All constraints are determinantal

Trek-separation:

{1,2,3} ⊥ {3,1,4} | ({1},{3})