The IV Regression Assumptions Include All of the Following with the Exception

Short Answer

The IV regression assumptions include all of the following with the exception of a. the error terms must be normally distributed.
b. $E \left( u _ { i } \mid W _ { 1 i } , \ldots , W _ { r i } \right) = 0$ .
c. Large outliers are unlikely: the $X$ 's, $W$ 's, $Z$ 's, and $Y$ 's all have nonzero, finite fourth moments.
d. $\left( X _ { 1 i } , \ldots , X _ { k i } , W _ { 1 i } , \ldots , W _ { r i } , Z _ { 1 i } , \ldots Z _ { m i } , Y _ { i } \right)$ are i.i.d. draws from their joint distribution.