[Limdep Nlogit List] GMXL (WTP space) in Nlogit

[Thamarasi Kularatne]

Hi,
I'm trying to run a generalised mixed logit model (GMXL) in WTP space in order to account for taste and scale heterogeneity.
As explained in the Nlogit 6 reference guide, we can choose one of the parameters in the GMXLOGIT model to have a coefficient of one and build this nonlinearity into the GMXLOGIT model by changing its type to (*type) in the ; Fcn = (*type),… specification.
In my case, I have 3 alternatives and the cost parameters need to be alternative specific. Therefore when estimating GMXL in WTP space, I need to specify 3 fixed parameters. example below:
GMXlogit ;userp
;lhs=choice,cset,altij
;choices=oral,inject,infuse,none
;pds=9 ;halton ;pts=10
;fcn=ocost(*n),icost(*n),ivcost(*n),eff(n),mild(n),inj_6m(n),spec(n)
;par
;pwt
;gmx
;cor
;gamma=0
;tau=0.1
;Model:
U(oral)=eff*eff+ oral_wee*oral_wee + oral_m*oral_mon + mild*mild_se + sev2*sev_2 + ocost*oralcost+ spec*spec+ oself*oral_sel /
U(inject)=inject+eff*eff+ inj_w*inj_week + inj_m*inj_mon + inj_6m*inj_6mon + inj_y*inj_yr + mild*mild_se + sev2*sev_2+ icost*injcost+ spec*spec+iadmin*admin_in /
U(infuse)=infuse+ eff*eff+ mild*mild_se + sev2*sev_2+ivcost*ivcost+ iv_6m*iv_6mon + iv_yr*iv_yr + spec*spec + ivadmin*admin_iv/
U(none)=None $
This does not work. Nlogit only takes one parameter at a time with a * in the fcn specification. Is there a way for me to run the GMXL in WTP space with 3 alternative specific cost parameters?
Thanks,Thames