Parameter: λ23 Identified

Algebraic Equations:

σ22λ2323,
σ12λ2313

Single Door Criterion:

{2} ⊥ {3,4} | {}
{2} ⊥ {3} | {1}

Instrumental Variable:

1 | {}

Parameter: λ34 Identified

Algebraic Equations:

σ23λ3424

Instrumental Variable:

2 | {}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω12 Identified

Algebraic Equations:

1212

Parameter: ω14 Identified

Algebraic Equations:

14σ2313σ2423ω14,
14σ2212σ2422ω14

Parameter: ω22 Identified

Algebraic Equations:

2222

Parameter: ω33 Identified

Algebraic Equations:

σ23222σ3322ω33,
σ13σ2312σ3312ω33

Parameter: ω34 Identified

Algebraic Equations:

σ24σ3323σ3423ω34

Parameter: ω44 Identified

Algebraic Equations:

242σ33+2σ23σ24σ34232σ44232ω44

Total Effect of X2 on X4: λ23λ34 Identified

Each Parameter Identified

Back Door Criterion:


{2} ⊥ {3,4} | {}

Vanishing Ideal


Constraint Set:

σ13σ2212σ23

All constraints are determinantal

Trek-separation:

{1,2} ⊥ {2,3} | ({},{2})