Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2,3,4} | {}

Parameter: λ23 Identified

Algebraic Equations:

σ12λ2313,
σ14σ22λ2314σ2313σ2412σ34

Instrumental Variable:

1 | {}

Parameter: λ24 Identified

Algebraic Equations:

σ12λ2414,
σ13σ22λ2414σ2313σ2412σ34

Instrumental Variable:

1 | {}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω23 Identified

Algebraic Equations:

σ13σ2412σ3414ω23,
σ13σ2212σ2312ω23

Parameter: ω24 Identified

Algebraic Equations:

σ14σ2312σ3413ω24,
σ14σ2212σ2412ω24

Parameter: ω33 Identified

Algebraic Equations:

σ14σ23213σ23σ2414σ22σ3312σ24σ3313σ22σ3412σ23σ3414σ22ω3312σ24ω33,
σ13σ14σ23132σ2412σ14σ3312σ13σ3412σ14ω33,
132σ22+2σ12σ13σ23122σ33122ω33

Parameter: ω44 Identified

Algebraic Equations:

14σ23σ2413σ24214σ22σ3412σ24σ3413σ22σ4412σ23σ4413σ22ω4412σ23ω44,
142σ2313σ14σ2412σ14σ3412σ13σ4412σ13ω44,
142σ22+2σ12σ14σ24122σ44122ω44

Total Effect of X1 on X3: λ12λ23 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,3,4} | {}

Total Effect of X1 on X4: λ12λ24 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,3,4} | {}

Vanishing Ideal


Constraint Set:

σ13σ14σ2212σ14σ2312σ13σ24122σ34

Non-determinantal constraints:

list non_determinantal = 1;

Trek-separation: