Parameter: λ12 Identified

Algebraic Equations:

σ13λ1223,
σ12σ14σ23λ1214σ22σ2312σ13σ24λ1211σ23σ24λ12122σ34λ1211σ22σ34λ12

Instrumental Variable:

3 | {}

Parameter: λ14 Identified

Algebraic Equations:

σ13σ22λ1412σ23λ1423σ2422σ34,
σ12σ13λ1411σ23λ1414σ2312σ34,
σ122λ1411σ22λ1414σ2212σ24

Single Door Criterion:

{1} ⊥ {4} | {2}
{1} ⊥ {4} | {2,3}

Instrumental Variable:

3 | {2}

Parameter: λ24 Identified

Algebraic Equations:

σ13σ22λ2412σ23λ2413σ2412σ34,
σ12σ13λ2413σ1411σ23λ2411σ34,
σ122λ2412σ1411σ22λ2411σ24

Single Door Criterion:

{2} ⊥ {4} | {1}
{2} ⊥ {4} | {1,3}

Instrumental Variable:

3 | {1}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω12 Identified

Algebraic Equations:

12σ1311σ2313ω12,
122σ14σ2311σ14σ22σ23122σ13σ2411σ12σ23σ24123σ3411σ12σ22σ3412σ14σ23ω1212σ13σ24ω1211σ23σ24ω12122σ34ω1211σ22σ34ω12

Parameter: ω13 Identified

Algebraic Equations:

1313

Parameter: ω22 Identified

Algebraic Equations:

132σ22+2σ12σ13σ2311σ232132ω22,
σ122σ14σ23211σ14σ22σ23212σ132σ22σ24122σ13σ23σ2411σ13σ22σ23σ2411σ12σ232σ24122σ13σ22σ3411σ13σ222σ34123σ23σ3411σ12σ22σ23σ3412σ13σ14σ23ω2212σ132σ24ω2211σ13σ23σ24ω22122σ13σ34ω2211σ13σ22σ34ω22,
σ122σ14σ22σ23211σ14σ222σ23212σ132σ222σ24122σ13σ22σ23σ2411σ13σ222σ23σ2411σ12σ22σ232σ24122σ13σ222σ3411σ13σ223σ34123σ22σ23σ3411σ12σ222σ23σ34122σ14σ232ω2212σ132σ22σ24ω22122σ13σ23σ24ω2211σ13σ22σ23σ24ω2211σ12σ232σ24ω22122σ13σ22σ34ω2211σ13σ222σ34ω22123σ23σ34ω2211σ12σ22σ23σ34ω22

Parameter: ω33 Identified

Algebraic Equations:

3333

Parameter: ω44 Identified

Algebraic Equations:

14σ23σ2413σ24214σ22σ3412σ24σ3413σ22σ4412σ23σ4413σ22ω4412σ23ω44,
142σ2313σ14σ2412σ14σ3411σ24σ3412σ13σ4411σ23σ4412σ13ω4411σ23ω44,
142σ22+2σ12σ14σ2411σ242122σ4411σ22σ44122ω4411σ22ω44

Total Effect of X1 on X4: λ12λ2414 Identified

Each Parameter Identified

Vanishing Ideal


Constraint Set:

σ13σ14σ2212σ14σ2312σ13σ2411σ23σ24122σ3411σ22σ34

All constraints are determinantal

Trek-separation:

{1,2,3} ⊥ {1,2,4} | ({},{1,2})