应该为835末尾和836页，但835页末尾的一句话我有点不理解：Changing the model  to a multinomial probit model based on the normal distribution, but still independent  and homoscedastic, does not solve the problem.
后面介绍三个备选模型中的MNP模型时： the greater generality of the multinomial probit is produced by the correlations across the alternatives (and, to a lesser extent, by the possible heteroscedasticity)
这是在说利用正态分布的MNP模型无法解决这个问题，其他分布的可以解决这个问题吗？