[Limdep Nlogit List] Structuring data to find interaction effects in choice models

[Avinandan Taron]

Dear All,

I am doing my PhD from Institute for Social and Economic Change, India. I am
doing a choice modelling exercise for finding out the willingness to pay for
canal irrigation in India. I am using four other attributes of canal
irrigation, and now plan for an interaction effect modelling. I have already
designed the choice experiment using SPSS and finished my data collection. I
am planning to use NLOGIT and STATA for the analysis. Since this is the
first time I am handling the data I need some suggestions from you all. I
have entered the data in excel.
Brief description of my choice modelling:
I have utilised the following attributes while conducting the choice
experiment - lined canal (categorical levels 1 and 0), number of times water
supplied through canals ( 3 levels), number of days water supplied ( 3
levels), average hrs of water supply ( 3 levels) and price for water (5
levels). I designed 32 choice sets which were divided into 4 blocks (thus
there are 8 choice sets in each block). These choice sets were presented in
form of choice cards to the farmers. In each choice card two of the choice
sets were included as alternatives along with the status quo (present case
scenario) and the farmer was thus asked to select from three alternatives
present in the show card. In this way each farmer was shown two choice
blocks (eight choice cards, 4 in each block) at the time of the survey. I
have entered the data in excel as 1 or 2 or 3 according to the choice of the
farmers for different alternatives in all the 4 choice cards of the block
(all total eight). I have considered three irrigation districts and 96
farmers from each district (all total of 288 farmers) for the study
Can anybody please suggest me a way ahead for further analysis of the data
set for restucturing the data for a main effect and two way interaction
effect?

Looking forward for the help.

with best regards.

Avinandan

-- 
Avinandan Taron
Research Fellow,
Institute for Social and Economic Change,
Bangalore - 560072.
Karnataka.