Hi Experts. The problem I am facing is this: Any person in my sample faces 5 choices: A, B, C, D, and E (we are unable to further group them to a smaller set), and (what's tricky is) this person can choose any combinations of these choices, for example, {A, B}, {C}, or even {A, B, C, D, E}. The question is: how to use a model and some covariates to predict/estimate sampled individuals' choices?. One way to do this is to list all possible combinations of choices and use some models such as multinomial logit to model/predict peoples' choices. But when the number of combination is large (theoretically, it's C5_1 + C5_2+C5_3+...+C5_5), the estimation could be messy. So, I wonder if there are neater ways to model people's choices? Many thanks.