
Parameter: λ12 Identified
Algebraic Equations:
σ11λ12-σ12
Single Door Criterion:
{1} ⊥ {2} | {}
Parameter: λ23 Identified
Algebraic Equations:
σ122λ23-σ12σ13-σ11σ22λ23+σ11σ23
Single Door Criterion:
{2} ⊥ {3} | {1}
Parameter: λ24 Identified
Algebraic Equations:
σ232λ24-σ22σ33λ24+σ24σ33-σ23σ34,
σ13σ23λ24-σ12σ33λ24+σ14σ33-σ13σ34,
σ13σ22λ24-σ12σ23λ24+σ14σ23-σ13σ24
Single Door Criterion:
{2} ⊥ {4} | {3}
{2} ⊥ {4} | {1,3}
Instrumental Variable:
1 | {3}
Parameter: λ34 Identified
Algebraic Equations:
σ232λ34-σ23σ24-σ22σ33λ34+σ22σ34,
σ13σ23λ34-σ14σ23-σ12σ33λ34+σ12σ34,
σ13σ22λ34-σ14σ22-σ12σ23λ34+σ12σ24
Single Door Criterion:
{3} ⊥ {4} | {2}
{3} ⊥ {4} | {1,2}
Instrumental Variable:
1 | {2}
Parameter: ω11 Identified
Algebraic Equations:
-σ11+ω11
Parameter: ω13 Identified
Algebraic Equations:
σ11σ13σ22-σ11σ12σ23+σ122ω13-σ11σ22ω13
Parameter: ω22 Identified
Algebraic Equations:
σ122-σ11σ22+σ11ω22
Parameter: ω33 Identified
Algebraic Equations:
-σ122σ132σ22+2σ123σ13σ23-2σ11σ122σ232+σ112σ22σ232-σ124σ33+2σ11σ122σ22σ33-σ112σ222σ33+σ124ω33-2σ11σ122σ22ω33+σ112σ222ω33
Parameter: ω44 Identified
Algebraic Equations:
-σ242σ33+2σ23σ24σ34-σ22σ342-σ232σ44+σ22σ33σ44+σ232ω44-σ22σ33ω44,
-σ14σ24σ33+σ14σ23σ34+σ13σ24σ34-σ12σ342-σ13σ23σ44+σ12σ33σ44+σ13σ23ω44-σ12σ33ω44,
-σ14σ23σ24+σ13σ242+σ14σ22σ34-σ12σ24σ34-σ13σ22σ44+σ12σ23σ44+σ13σ22ω44-σ12σ23ω44
Total Effect of X1 on X3: λ12λ23 Identified
Each Parameter Identified
Total Effect of X1 on X4: λ12λ23λ34+λ12λ24 Identified
Each Parameter Identified
Total Effect of X2 on X4: λ23λ34+λ24 Identified
Each Parameter Identified
Back Door Criterion:
{2} ⊥ {3,4} | {1}
Constraint Set:
σ14σ232-σ13σ23σ24-σ14σ22σ33+σ12σ24σ33+σ13σ22σ34-σ12σ23σ34
All constraints are determinantal
Trek-separation:
{1,2,3} ⊥ {2,3,4} | ({},{2,3})
Algebraic Equations:
σ11λ12-σ12
Single Door Criterion:
{1} ⊥ {2} | {}
Parameter: λ23 Identified
Algebraic Equations:
σ122λ23-σ12σ13-σ11σ22λ23+σ11σ23
Single Door Criterion:
{2} ⊥ {3} | {1}
Parameter: λ24 Identified
Algebraic Equations:
σ232λ24-σ22σ33λ24+σ24σ33-σ23σ34,
σ13σ23λ24-σ12σ33λ24+σ14σ33-σ13σ34,
σ13σ22λ24-σ12σ23λ24+σ14σ23-σ13σ24
Single Door Criterion:
{2} ⊥ {4} | {3}
{2} ⊥ {4} | {1,3}
Instrumental Variable:
1 | {3}
Parameter: λ34 Identified
Algebraic Equations:
σ232λ34-σ23σ24-σ22σ33λ34+σ22σ34,
σ13σ23λ34-σ14σ23-σ12σ33λ34+σ12σ34,
σ13σ22λ34-σ14σ22-σ12σ23λ34+σ12σ24
Single Door Criterion:
{3} ⊥ {4} | {2}
{3} ⊥ {4} | {1,2}
Instrumental Variable:
1 | {2}
Parameter: ω11 Identified
Algebraic Equations:
-σ11+ω11
Parameter: ω13 Identified
Algebraic Equations:
σ11σ13σ22-σ11σ12σ23+σ122ω13-σ11σ22ω13
Parameter: ω22 Identified
Algebraic Equations:
σ122-σ11σ22+σ11ω22
Parameter: ω33 Identified
Algebraic Equations:
-σ122σ132σ22+2σ123σ13σ23-2σ11σ122σ232+σ112σ22σ232-σ124σ33+2σ11σ122σ22σ33-σ112σ222σ33+σ124ω33-2σ11σ122σ22ω33+σ112σ222ω33
Parameter: ω44 Identified
Algebraic Equations:
-σ242σ33+2σ23σ24σ34-σ22σ342-σ232σ44+σ22σ33σ44+σ232ω44-σ22σ33ω44,
-σ14σ24σ33+σ14σ23σ34+σ13σ24σ34-σ12σ342-σ13σ23σ44+σ12σ33σ44+σ13σ23ω44-σ12σ33ω44,
-σ14σ23σ24+σ13σ242+σ14σ22σ34-σ12σ24σ34-σ13σ22σ44+σ12σ23σ44+σ13σ22ω44-σ12σ23ω44
Total Effect of X1 on X3: λ12λ23 Identified
Each Parameter Identified
Total Effect of X1 on X4: λ12λ23λ34+λ12λ24 Identified
Each Parameter Identified
Total Effect of X2 on X4: λ23λ34+λ24 Identified
Each Parameter Identified
Back Door Criterion:
{2} ⊥ {3,4} | {1}
Vanishing Ideal
Constraint Set:
σ14σ232-σ13σ23σ24-σ14σ22σ33+σ12σ24σ33+σ13σ22σ34-σ12σ23σ34
All constraints are determinantal
Trek-separation:
{1,2,3} ⊥ {2,3,4} | ({},{2,3})