Parameter: λ13 Identified

Algebraic Equations:

σ14λ1334,
σ11λ1313

Single Door Criterion:

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

Instrumental Variable:

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

Parameter: λ24

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω14 Identified

Algebraic Equations:

1414

Parameter: ω22 Identified

Algebraic Equations:

2222

Parameter: ω24

Parameter: ω33 Identified

Algebraic Equations:

14σ3313σ3414ω33,
σ13211σ3311ω33

Parameter: ω44

Vanishing Ideal


Constraint Set:

σ23,
σ12,
σ13σ1411σ34

All constraints are determinantal

Trek-separation:

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