Parameter: λ₁₂ Identified

Algebraic Equations:

σ₁₁λ₁₂-σ₁₂

Single Door Criterion:

{1} ⊥ {2} | {}

Parameter: λ₁₃

Parameter: λ₁₄ Identified

Algebraic Equations:

σ₁₃σ₂₂λ₁₄-σ₁₂σ₂₃λ₁₄+σ₂₃σ₂₄-σ₂₂σ₃₄,
σ₁₂σ₁₃λ₁₄-σ₁₁σ₂₃λ₁₄+σ₁₄σ₂₃-σ₁₂σ₃₄,
σ₁₂²λ₁₄-σ₁₁σ₂₂λ₁₄+σ₁₄σ₂₂-σ₁₂σ₂₄

Single Door Criterion:

{1} ⊥ {4} | {2}
{1} ⊥ {4} | {2,3}

Instrumental Variable:

3 | {2}

Parameter: λ₂₄ Identified

Algebraic Equations:

σ₁₃σ₂₂λ₂₄-σ₁₂σ₂₃λ₂₄-σ₁₃σ₂₄+σ₁₂σ₃₄,
σ₁₂σ₁₃λ₂₄-σ₁₃σ₁₄-σ₁₁σ₂₃λ₂₄+σ₁₁σ₃₄,
σ₁₂²λ₂₄-σ₁₂σ₁₄-σ₁₁σ₂₂λ₂₄+σ₁₁σ₂₄

Single Door Criterion:

{2} ⊥ {4} | {1}
{2} ⊥ {4} | {1,3}

Instrumental Variable:

3 | {1}

Parameter: ω₁₁ Identified

Algebraic Equations:

-σ₁₁+ω₁₁

Parameter: ω₁₃

Parameter: ω₂₂ Identified

Algebraic Equations:

σ₁₂²-σ₁₁σ₂₂+σ₁₁ω₂₂

Parameter: ω₂₃ Identified

Algebraic Equations:

σ₁₂σ₁₃-σ₁₁σ₂₃+σ₁₁ω₂₃

Parameter: ω₃₃

Parameter: ω₄₄ Identified

Algebraic Equations:

-σ₁₄σ₂₃σ₂₄+σ₁₃σ₂₄²+σ₁₄σ₂₂σ₃₄-σ₁₂σ₂₄σ₃₄-σ₁₃σ₂₂σ₄₄+σ₁₂σ₂₃σ₄₄+σ₁₃σ₂₂ω₄₄-σ₁₂σ₂₃ω₄₄,
-σ₁₄²σ₂₃+σ₁₃σ₁₄σ₂₄+σ₁₂σ₁₄σ₃₄-σ₁₁σ₂₄σ₃₄-σ₁₂σ₁₃σ₄₄+σ₁₁σ₂₃σ₄₄+σ₁₂σ₁₃ω₄₄-σ₁₁σ₂₃ω₄₄,
-σ₁₄²σ₂₂+2σ₁₂σ₁₄σ₂₄-σ₁₁σ₂₄²-σ₁₂²σ₄₄+σ₁₁σ₂₂σ₄₄+σ₁₂²ω₄₄-σ₁₁σ₂₂ω₄₄

Total Effect of X₁ on X₄: λ₁₂λ₂₄+λ₁₄ Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,4} | {}

Vanishing Ideal

Constraint Set:

σ₁₃σ₁₄σ₂₂-σ₁₂σ₁₄σ₂₃-σ₁₂σ₁₃σ₂₄+σ₁₁σ₂₃σ₂₄+σ₁₂²σ₃₄-σ₁₁σ₂₂σ₃₄

All constraints are determinantal

Trek-separation:

{1,2,3} ⊥ {1,2,4} | ({},{1,2})