Test for complete separation (or quasi-) in the Cox logistic regression problem Example 9.7. What happens if we change the response at the last design point to y4 = 16? Find the conditions for...

Test for complete separation (or quasi-) in the Cox logistic regression problem Example 9.7. What happens if we change the response at the last design point to y4 = 16?

Find the conditions for complete separation in the probit model, where P r(Yi = 1|xi) = (xT i β) where  is the standard normal cdf. (See Stokes, 2004 for an interesting application.)