Skip to main content
Cross Validated

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

Required fields*

3
  • $\begingroup$ Since the 1st condition also is stronger than the usual one, it would be helpful if you could provide the reference for these two conditions. $\endgroup$ Commented May 16, 2014 at 19:53
  • $\begingroup$ Wooldridge, §5.1.1 $\endgroup$ Commented May 16, 2014 at 20:58
  • $\begingroup$ Um... in Wooldridge condition 1) is $\text{Cov}(z_1,u)=0$. In my copy at least ;-) $\endgroup$ Commented May 16, 2014 at 21:34