The discrete choice model has often been used in studies of consumer preference. Consider the following experiment (SAS Institute 1995). Ten people were each given eight chocolate bars with varying characteristics. After eating the bars, they were asked to choose the one they liked best. The bars were distinguished by the following variables:
DARK 0=milk chocolate, 1=dark chocolate
SOFT 0=hard center, 1=soft center
NUTS 0=no nuts, 1=nuts
Each subject tasted eight chocolate bars with all possible combinations of these characteristics. The aim was to determine which characteristics of the bars affected people’s choices. Here are the data:
DATA my.chocs; INPUT id choose dark soft nuts @@; DATALINES; 1 0 0 0 0 1 0 0 0 1 ...