Hi, I want to know is there other functions in R to estimate qualitative response model besides multinom() in library nnet, if this is the only possibility, I have a question about the application: for example: there is three transportation choice : car, bus , subway. each alternative has own characteristic variables, I want to apply conditional logit model to analysis the choice of three alternatives, but if some cases face different choice set, i.e only car and bus are available, how to use this function? I am a newcomer in R, hope the simple question not to bother you. thanks for the help.
On 14-Jul-03 Z Eric wrote:> Hi, I want to know is there other functions in R to > estimate qualitative response model besides multinom() > in library nnet, if this is the only possibility, I > have a question about the application: > for example: > there is three transportation choice : car, bus, subway. > each alternative has own characteristic variables, > I want to apply conditional logit model to analysis > the choice of three alternatives, but if some cases > face different choice set, i.e only car and bus are > available, how to use this function? > I am a newcomer in R, hope the simple question not to > bother you. > thanks for the help.A totally naive idea would be to incorporate the "choice" set as a set of three factors CAR=0/1, BUS=0/1, SUB=0/1 according to availability. Naively, since (e.g.) CAR=0 would lead to zero cases observed, one might expect that the estimation would predict zero for these. However, in conjunction with the logistic model the parameter estimates would be improper (-> inf). Nevertheless, there may be some mileage in an approach which incorporated this idea, though I'm not seeing how! If it could be got to work, though, it should lead to a convenient representation of interesting interactions, e.g. how does propensity to use "car" change if "subway" is not available? Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 167 1972 Date: 14-Jul-03 Time: 14:14:22 ------------------------------ XFMail ------------------------------
On 14 Jul 2003 at 14:14, Ted Harding wrote: Another possibility could be to try MCMCprobit or MCMClogit in package MCMCPack on CRAN. Kjetil Halvorsen> On 14-Jul-03 Z Eric wrote: > > Hi, I want to know is there other functions in R to > > estimate qualitative response model besides multinom() > > in library nnet, if this is the only possibility, I > > have a question about the application: > > for example: > > there is three transportation choice : car, bus, subway. > > each alternative has own characteristic variables, > > I want to apply conditional logit model to analysis > > the choice of three alternatives, but if some cases > > face different choice set, i.e only car and bus are > > available, how to use this function? > > I am a newcomer in R, hope the simple question not to > > bother you. > > thanks for the help. > > A totally naive idea would be to incorporate the "choice" > set as a set of three factors CAR=0/1, BUS=0/1, SUB=0/1 > according to availability. Naively, since (e.g.) CAR=0 > would lead to zero cases observed, one might expect that > the estimation would predict zero for these. However, in > conjunction with the logistic model the parameter estimates > would be improper (-> inf). > > Nevertheless, there may be some mileage in an approach which > incorporated this idea, though I'm not seeing how! > > If it could be got to work, though, it should lead to a convenient > representation of interesting interactions, e.g. how does propensity > to use "car" change if "subway" is not available? > > Ted. > > > -------------------------------------------------------------------- > E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk> > Fax-to-email: +44 (0)870 167 1972 > Date: 14-Jul-03 Time: 14:14:22 > ------------------------------ XFMail ------------------------------ > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help