Parameter: λ12 Identified

Algebraic Equations:

σ11λ1212

Single Door Criterion:

{1} ⊥ {2,3} | {}

Parameter: λ23 Identified

Algebraic Equations:

σ24λ2334,
σ22λ2323,
σ12λ2313

Single Door Criterion:

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

Instrumental Variable:

1 | {}
1 | {4}
4 | {}
4 | {1}

Parameter: λ24 Identified

Algebraic Equations:

σ12σ13λ2413σ1411σ23λ2411σ34,
σ122λ2412σ1411σ22λ2411σ24

Single Door Criterion:

{2} ⊥ {4} | {1}
{2} ⊥ {4} | {1,3}

Instrumental Variable:

3 | {1}

Parameter: ω11 Identified

Algebraic Equations:

1111

Parameter: ω14 Identified

Algebraic Equations:

σ11σ14σ2311σ12σ3412σ13ω1411σ23ω14,
σ11σ14σ2211σ12σ24122ω1411σ22ω14

Parameter: ω22 Identified

Algebraic Equations:

σ12211σ2211ω22

Parameter: ω33 Identified

Algebraic Equations:

24σ3323σ3424ω33,
σ23222σ3322ω33,
σ13σ2312σ3312ω33

Parameter: ω44 Identified

Algebraic Equations:

12σ13σ142σ23+2σ122σ13σ14σ34-2σ11σ122σ342112σ22σ342122σ132σ44+2σ11σ12σ13σ23σ44112σ232σ44122σ132ω44-2σ11σ12σ13σ23ω44112σ232ω44,
122σ142σ23+2σ123σ14σ34-2σ11σ122σ24σ34112σ22σ24σ34123σ13σ44+2σ11σ122σ23σ44112σ22σ23σ44123σ13ω44-2σ11σ122σ23ω44112σ22σ23ω44,
122σ142σ22+2σ123σ14σ24-2σ11σ122σ242112σ22σ242124σ44+2σ11σ122σ22σ44112σ222σ44124ω44-2σ11σ122σ22ω44112σ222ω44

Total Effect of X1 on X3: λ12λ23 Identified

Each Parameter Identified

Back Door Criterion:


{1} ⊥ {2,3} | {}

Total Effect of X1 on X4: λ12λ24 Identified

Each Parameter Identified

Vanishing Ideal


Constraint Set:

σ23σ2422σ34,
σ13σ2412σ34,
σ13σ2212σ23

All constraints are determinantal

Trek-separation:

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