[gov2001-l] a question on multinominal logistic models

Hi folks, Sorry for troubling you guys. Hopefully somebody here can give me some advice on the method of multinominal logistic model. Your help will be deeply appreciated. Best, Yanbo Question: What is the minimum number of observations required per category given n independent variables? Is the rule the same in MLR as it is for a logistic regression model (~20 observations per independent variable) for the entire MLR (i.e., all of the nominal categories combined) or, since each nominal category is a separate equation, does that imply that the number of observations per category be at least 20*(the number of independent variables).