Parameter: λ₁₃ Identified

Algebraic Equations:

σ₁₄λ₁₃-σ₃₄,
σ₁₂λ₁₃-σ₂₃

Instrumental Variable:

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

Parameter: λ₂₄ Identified

Algebraic Equations:

σ₂₂λ₂₄-σ₂₄

Single Door Criterion:

{2} ⊥ {4} | {}

Parameter: ω₁₁ Identified

Algebraic Equations:

-σ₁₁+ω₁₁

Parameter: ω₁₂ Identified

Algebraic Equations:

-σ₁₂+ω₁₂

Parameter: ω₁₃ Identified

Algebraic Equations:

-σ₁₃σ₁₄+σ₁₁σ₃₄+σ₁₄ω₁₃,
-σ₁₂σ₁₃+σ₁₁σ₂₃+σ₁₂ω₁₃

Parameter: ω₁₄ Identified

Algebraic Equations:

-σ₁₄σ₂₂+σ₁₂σ₂₄+σ₂₂ω₁₄

Parameter: ω₂₂ Identified

Algebraic Equations:

-σ₂₂+ω₂₂

Parameter: ω₃₃ Identified

Algebraic Equations:

-σ₁₄²σ₃₃+2σ₁₃σ₁₄σ₃₄-σ₁₁σ₃₄²+σ₁₄²ω₃₃,
-σ₁₂σ₁₄σ₃₃+2σ₁₂σ₁₃σ₃₄-σ₁₁σ₂₃σ₃₄+σ₁₂σ₁₄ω₃₃,
2σ₁₂σ₁₃σ₂₃-σ₁₁σ₂₃²-σ₁₂²σ₃₃+σ₁₂²ω₃₃

Parameter: ω₄₄ Identified

Algebraic Equations:

σ₂₄²-σ₂₂σ₄₄+σ₂₂ω₄₄

Vanishing Ideal

Constraint Set:

σ₁₄σ₂₃-σ₁₂σ₃₄

All constraints are determinantal

Trek-separation:

{1,3} ⊥ {2,4} | ({1},{})