The model in the second setup, called Model 2, uses standard normal variables with dependence structure both within
and between groups. In particular, the variables in groups 1, 3, 4 and 5 are generated as a 20 dimensional Gaussian
distribution with mean 0, variance 1 and covariance 0.8; the variables in groups 2, 6, 7 and 8 are generated similarly. The
response variable is related to 2 groups through the relation