Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2} | {}

Parameter: λ14 Identified

Algebraic Equations:

σ13σ22λ1412σ23λ1423σ2422σ34,
σ12σ13λ1411σ23λ1414σ2312σ34,
σ122λ1411σ22λ1414σ2212σ24

Single Door Criterion:

{1} ⊥ {4} | {2}
{1} ⊥ {4} | {2,3}

Instrumental Variable:

3 | {2}

Parameter: λ23 Identified

Algebraic Equations:

σ14σ22λ2314σ2312σ24λ2312σ34,
σ12σ14λ2313σ1411σ24λ2311σ34,
σ122λ2312σ1311σ22λ2311σ23

Single Door Criterion:

{2} ⊥ {3} | {1}
{2} ⊥ {3} | {1,4}

Instrumental Variable:

4 | {1}

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: ω13 Identified

Algebraic Equations:

σ11σ23σ2411σ22σ3414σ22ω1312σ24ω13,
σ11σ13σ2411σ12σ3412σ14ω1311σ24ω13,
σ11σ13σ2211σ12σ23122ω1311σ22ω13

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33 Identified

Algebraic Equations:

σ142σ22σ232-2σ12σ14σ232σ24142σ222σ33+2σ12σ14σ22σ24σ33122σ242σ33+2σ122σ23σ24σ34122σ22σ342142σ222ω33-2σ12σ14σ22σ24ω33122σ242ω33,
σ12σ142σ23212σ13σ14σ23σ2411σ14σ232σ2412σ142σ22σ33122σ14σ24σ3311σ14σ22σ24σ3311σ12σ242σ33122σ13σ24σ3411σ12σ23σ24σ34123σ34212σ142σ22ω33122σ14σ24ω3311σ14σ22σ24ω3311σ12σ242ω33,
σ122σ14σ23211σ14σ22σ232122σ13σ23σ2411σ12σ232σ24122σ14σ22σ3311σ14σ222σ33123σ24σ3311σ12σ22σ24σ33122σ13σ22σ34123σ23σ34122σ14σ22ω3311σ14σ222ω33123σ24ω3311σ12σ22σ24ω33,
σ12σ13σ142σ2312σ132σ14σ2411σ13σ14σ23σ24122σ142σ33+2σ11σ12σ14σ24σ33112σ242σ33122σ13σ14σ3411σ12σ14σ23σ3411σ12σ13σ24σ34112σ23σ24σ3411σ122σ342122σ142ω33-2σ11σ12σ14σ24ω33112σ242ω33,
σ122σ13σ14σ2311σ12σ14σ232122σ132σ24112σ232σ24123σ14σ3311σ12σ14σ22σ3311σ122σ24σ33112σ22σ24σ33123σ13σ3411σ122σ23σ34123σ14ω3311σ12σ14σ22ω3311σ122σ24ω33112σ22σ24ω33,
122σ132σ22+2σ123σ13σ23-2σ11σ122σ232112σ22σ232124σ33+2σ11σ122σ22σ33112σ222σ33124ω33-2σ11σ122σ22ω33112σ222ω33

Parameter: ω44 Identified

Algebraic Equations:

14σ23σ2413σ24214σ22σ3412σ24σ3413σ22σ4412σ23σ4413σ22ω4412σ23ω44,
142σ2313σ14σ2412σ14σ3411σ24σ3412σ13σ4411σ23σ4412σ13ω4411σ23ω44,
142σ22+2σ12σ14σ2411σ242122σ4411σ22σ44122ω4411σ22ω44

Total Effect of X1 on X3: λ12λ23 Identified

Each Parameter Identified

Total Effect of X1 on X4: λ12λ2414 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,4} | {}

Vanishing Ideal


Constraint Set:

σ13σ14σ2212σ14σ2312σ13σ2411σ23σ24122σ3411σ22σ34

All constraints are determinantal

Trek-separation:

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