Parameter: λ₁₂ Identified

Algebraic Equations:

σ₁₃λ₁₂-σ₂₃,
σ₁₁λ₁₂-σ₁₂

Single Door Criterion:

{1} ⊥ {2} | {}
{1} ⊥ {2} | {3}

Instrumental Variable:

3 | {}

Parameter: λ₁₃ Identified

Algebraic Equations:

σ₁₄λ₁₃-σ₃₄,
σ₁₂λ₁₃-σ₂₃,
σ₁₁λ₁₃-σ₁₃

Single Door Criterion:

{1} ⊥ {3} | {}
{1} ⊥ {3} | {4}
{1} ⊥ {3} | {2}
{1} ⊥ {3} | {2,4}

Instrumental Variable:

2 | {}
2 | {4}
4 | {}
4 | {2}

Parameter: λ₂₄ Identified

Algebraic Equations:

σ₁₃σ₂₂λ₂₄-σ₁₂σ₂₃λ₂₄-σ₁₃σ₂₄+σ₁₂σ₃₄,
σ₁₂²λ₂₄-σ₁₂σ₁₄-σ₁₁σ₂₂λ₂₄+σ₁₁σ₂₄

Single Door Criterion:

{2} ⊥ {3,4} | {1}
{2} ⊥ {4} | {1,3}

Parameter: ω₁₁ Identified

Algebraic Equations:

-σ₁₁+ω₁₁

Parameter: ω₁₄ Identified

Algebraic Equations:

σ₁₁σ₂₃σ₂₄-σ₁₁σ₂₂σ₃₄+σ₁₃σ₂₂ω₁₄-σ₁₂σ₂₃ω₁₄,
σ₁₁σ₁₄σ₂₂-σ₁₁σ₁₂σ₂₄+σ₁₂²ω₁₄-σ₁₁σ₂₂ω₁₄

Parameter: ω₂₂ Identified

Algebraic Equations:

-σ₁₃σ₂₂+σ₁₂σ₂₃+σ₁₃ω₂₂,
σ₁₂²-σ₁₁σ₂₂+σ₁₁ω₂₂

Parameter: ω₃₃ Identified

Algebraic Equations:

-σ₁₄σ₃₃+σ₁₃σ₃₄+σ₁₄ω₃₃,
σ₁₃σ₂₃-σ₁₂σ₃₃+σ₁₂ω₃₃,
σ₁₃²-σ₁₁σ₃₃+σ₁₁ω₃₃

Parameter: ω₄₄ Identified

Algebraic Equations:

σ₁₃²σ₂₂σ₂₄²-2σ₁₁σ₂₃²σ₂₄²+2σ₁₂²σ₂₃σ₂₄σ₃₄-σ₁₂²σ₂₂σ₃₄²-σ₁₃²σ₂₂²σ₄₄-σ₁₂²σ₂₃²σ₄₄+2σ₁₁σ₂₂σ₂₃²σ₄₄+σ₁₃²σ₂₂²ω₄₄+σ₁₂²σ₂₃²ω₄₄-2σ₁₁σ₂₂σ₂₃²ω₄₄,
σ₁₁σ₁₃σ₂₂σ₂₄²-2σ₁₁σ₁₂σ₂₃σ₂₄²-σ₁₂²σ₁₄σ₂₂σ₃₄+2σ₁₂³σ₂₄σ₃₄-σ₁₁σ₁₃σ₂₂²σ₄₄-σ₁₂³σ₂₃σ₄₄+2σ₁₁σ₁₂σ₂₂σ₂₃σ₄₄+σ₁₁σ₁₃σ₂₂²ω₄₄+σ₁₂³σ₂₃ω₄₄-2σ₁₁σ₁₂σ₂₂σ₂₃ω₄₄,
-σ₁₂²σ₁₄²σ₂₂+2σ₁₂³σ₁₄σ₂₄-2σ₁₁σ₁₂²σ₂₄²+σ₁₁²σ₂₂σ₂₄²-σ₁₂⁴σ₄₄+2σ₁₁σ₁₂²σ₂₂σ₄₄-σ₁₁²σ₂₂²σ₄₄+σ₁₂⁴ω₄₄-2σ₁₁σ₁₂²σ₂₂ω₄₄+σ₁₁²σ₂₂²ω₄₄

Total Effect of X₁ on X₄: λ₁₂λ₂₄ Identified

Each Parameter Identified

Vanishing Ideal

Constraint Set:

σ₁₄σ₂₃-σ₁₂σ₃₄,
σ₁₃σ₁₄-σ₁₁σ₃₄,
σ₁₂σ₁₃-σ₁₁σ₂₃

All constraints are determinantal

Trek-separation:

{1,2} ⊥ {1,3} | ({1},{})
{1,3} ⊥ {1,2,4} | ({1},{})
{1,2,3} ⊥ {1,2,4} | ({1,2},{})
{1,4,3} ⊥ {1,2,4} | ({1,4},{})
{1,2,3} ⊥ {2,1,4} | ({1},{2})