defining a base category
Posted: 09 Dec 2021, 16:54
Hello,
I have a basic question about defining utility functions in Apollo. When we want to fit a multinomial logit regression, should we consider one of the alternatives as a base category like this?
V[["A"]]= b_cov*cov_A + b_acc1*acc1_A + b_acc2*acc2_A + b_bid * bid_A
V[["B"]]= b_cov*cov_B + b_acc1*acc1_B + b_acc2*acc2_B + b_bid * bid_B
V[["C"]]= 0
Or should we define them like below? (as in most of the examples in apollo "http://www.apollochoicemodelling.com/examples.html")
V[["A"]]= b_cov*cov_A + b_acc1*acc1_A + b_acc2*acc2_A + b_bid * bid_A
V[["B"]]= b_cov*cov_B + b_acc1*acc1_B + b_acc2*acc2_B + b_bid * bid_B
V[["C"]]= b_cov*cov_C + b_acc1*acc1_C + b_acc2*acc2_C + b_bid * bid_C
Thanks,
I have a basic question about defining utility functions in Apollo. When we want to fit a multinomial logit regression, should we consider one of the alternatives as a base category like this?
V[["A"]]= b_cov*cov_A + b_acc1*acc1_A + b_acc2*acc2_A + b_bid * bid_A
V[["B"]]= b_cov*cov_B + b_acc1*acc1_B + b_acc2*acc2_B + b_bid * bid_B
V[["C"]]= 0
Or should we define them like below? (as in most of the examples in apollo "http://www.apollochoicemodelling.com/examples.html")
V[["A"]]= b_cov*cov_A + b_acc1*acc1_A + b_acc2*acc2_A + b_bid * bid_A
V[["B"]]= b_cov*cov_B + b_acc1*acc1_B + b_acc2*acc2_B + b_bid * bid_B
V[["C"]]= b_cov*cov_C + b_acc1*acc1_C + b_acc2*acc2_C + b_bid * bid_C
Thanks,