Before revision:  We provide conditions for consistency of this estimator when either n or T or both divergeto infinity, and when the answers of each subject are correlated and this correlation differs across subjects. We further demonstrate that the rate of convergence depends upon the covariance structure of the error term taken across individuals.
After revision:  We provide conditions for consistency when either nor Tor both diverge. The rate of convergence depends upon the covariance structure of the error term taken across individuals.