Parameter: λ₁₃ Identified

Algebraic Equations:

σ₁₁λ₁₃-σ₁₃

Single Door Criterion:

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

Parameter: λ₂₄ Identified

Algebraic Equations:

σ₂₃λ₂₄-σ₃₄

Instrumental Variable:

1 | {3}
3 | {}
3 | {1}

Parameter: ω₁₁ Identified

Algebraic Equations:

-σ₁₁+ω₁₁

Parameter: ω₂₂ Identified

Algebraic Equations:

-σ₂₂+ω₂₂

Parameter: ω₂₃ Identified

Algebraic Equations:

-σ₂₃+ω₂₃

Parameter: ω₂₄ Identified

Algebraic Equations:

-σ₂₃σ₂₄+σ₂₂σ₃₄+σ₂₃ω₂₄

Parameter: ω₃₃ Identified

Algebraic Equations:

σ₁₃²-σ₁₁σ₃₃+σ₁₁ω₃₃

Parameter: ω₄₄ Identified

Algebraic Equations:

2σ₂₃σ₂₄σ₃₄-σ₂₂σ₃₄²-σ₂₃²σ₄₄+σ₂₃²ω₄₄

Vanishing Ideal

Constraint Set:

σ₁₄,
σ₁₂

All constraints are determinantal

Trek-separation:

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