How does a local instrumental variable method perform across settings with instruments of differing strengths? A simulation study and an evaluation of emergency surgery

. 2023 Jun 11;32(9):2113–2126. doi: 10.1002/hec.4719

(A2)

Unconfoundedness of Z

(Y_{d_{z}}, D_{z}) ⊥ Z | X_{O}

(A3)

Exclusion restriction

Y_{d_{z}} = Y_{d}

with probability 1

(A4)

Relevance

0 < P (Z = z) < 1

(A5)

Monotonicity

z^{'} > z

then

D_{z^{'}} \geq D_{z}

with probability 1

(A6)

Stable unit treatment value assumption

{D = D}_{Z}

and

{Y = Y}_{D}