
Parameter: λ12 Identified
Algebraic Equations:
σ11λ12-σ12
Single Door Criterion:
{1} ⊥ {2,3} | {}
Parameter: λ23 Identified
Algebraic Equations:
σ24λ23-σ34,
σ22λ23-σ23,
σ12λ23-σ13
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:
σ12σ13λ24-σ13σ14-σ11σ23λ24+σ11σ34,
σ122λ24-σ12σ14-σ11σ22λ24+σ11σ24
Single Door Criterion:
{2} ⊥ {4} | {1}
{2} ⊥ {4} | {1,3}
Instrumental Variable:
3 | {1}
Parameter: ω11 Identified
Algebraic Equations:
-σ11+ω11
Parameter: ω14 Identified
Algebraic Equations:
σ11σ14σ23-σ11σ12σ34+σ12σ13ω14-σ11σ23ω14,
σ11σ14σ22-σ11σ12σ24+σ122ω14-σ11σ22ω14
Parameter: ω22 Identified
Algebraic Equations:
σ122-σ11σ22+σ11ω22
Parameter: ω33 Identified
Algebraic Equations:
-σ24σ33+σ23σ34+σ24ω33,
σ232-σ22σ33+σ22ω33,
σ13σ23-σ12σ33+σ12ω33
Parameter: ω44 Identified
Algebraic Equations:
-σ12σ13σ142σ23+2σ122σ13σ14σ34-2σ11σ122σ342+σ112σ22σ342-σ122σ132σ44+2σ11σ12σ13σ23σ44-σ112σ232σ44+σ122σ132ω44-2σ11σ12σ13σ23ω44+σ112σ232ω44,
-σ122σ142σ23+2σ123σ14σ34-2σ11σ122σ24σ34+σ112σ22σ24σ34-σ123σ13σ44+2σ11σ122σ23σ44-σ112σ22σ23σ44+σ123σ13ω44-2σ11σ122σ23ω44+σ112σ22σ23ω44,
-σ122σ142σ22+2σ123σ14σ24-2σ11σ122σ242+σ112σ22σ242-σ124σ44+2σ11σ122σ22σ44-σ112σ222σ44+σ124ω44-2σ11σ122σ22ω44+σ112σ222ω44
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
Constraint Set:
σ23σ24-σ22σ34,
σ13σ24-σ12σ34,
σ13σ22-σ12σ23
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})
Algebraic Equations:
σ11λ12-σ12
Single Door Criterion:
{1} ⊥ {2,3} | {}
Parameter: λ23 Identified
Algebraic Equations:
σ24λ23-σ34,
σ22λ23-σ23,
σ12λ23-σ13
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:
σ12σ13λ24-σ13σ14-σ11σ23λ24+σ11σ34,
σ122λ24-σ12σ14-σ11σ22λ24+σ11σ24
Single Door Criterion:
{2} ⊥ {4} | {1}
{2} ⊥ {4} | {1,3}
Instrumental Variable:
3 | {1}
Parameter: ω11 Identified
Algebraic Equations:
-σ11+ω11
Parameter: ω14 Identified
Algebraic Equations:
σ11σ14σ23-σ11σ12σ34+σ12σ13ω14-σ11σ23ω14,
σ11σ14σ22-σ11σ12σ24+σ122ω14-σ11σ22ω14
Parameter: ω22 Identified
Algebraic Equations:
σ122-σ11σ22+σ11ω22
Parameter: ω33 Identified
Algebraic Equations:
-σ24σ33+σ23σ34+σ24ω33,
σ232-σ22σ33+σ22ω33,
σ13σ23-σ12σ33+σ12ω33
Parameter: ω44 Identified
Algebraic Equations:
-σ12σ13σ142σ23+2σ122σ13σ14σ34-2σ11σ122σ342+σ112σ22σ342-σ122σ132σ44+2σ11σ12σ13σ23σ44-σ112σ232σ44+σ122σ132ω44-2σ11σ12σ13σ23ω44+σ112σ232ω44,
-σ122σ142σ23+2σ123σ14σ34-2σ11σ122σ24σ34+σ112σ22σ24σ34-σ123σ13σ44+2σ11σ122σ23σ44-σ112σ22σ23σ44+σ123σ13ω44-2σ11σ122σ23ω44+σ112σ22σ23ω44,
-σ122σ142σ22+2σ123σ14σ24-2σ11σ122σ242+σ112σ22σ242-σ124σ44+2σ11σ122σ22σ44-σ112σ222σ44+σ124ω44-2σ11σ122σ22ω44+σ112σ222ω44
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:
σ23σ24-σ22σ34,
σ13σ24-σ12σ34,
σ13σ22-σ12σ23
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})