20 CHAPTER 3 REVIEW OF CONJOINT ANALYSIS THEORY ...

demographic characteristics such as education, age income, ethnic origin, and gender. An
ordered probit model is used to estimate consumer preferences for these labeling
attributes which included the demographic variables. The following empirical model was
used:
R n,i = β 0 + β 1 X 1 + β 2 X2 + β 3 X3 + β 4 X 4 + 5 EDU ij + 6 Age ij + 7 INC ij + 8 RACE ij
+ 9 GEN ij +ε n
where, R n,i is the n th respondent’s rating (0 –10 scale) of the i th labeling format, o is the
constant term, and i represents the part-worth estimates for each of the attributes-levels.
The right hand variables are coded as follows: X1= 1, X2 = 0, if the text disclosure
describes the benefits of biotech ingredients contained in the product; X1= 0, X2= 1 for
simple text disclosure, which states the product contains biotech ingredients, and X1= -1,
X2 = -1 if no text disclosure is present. The logo’s location attribute is coded as follows;
X3 = 1 if the logo appears on the primary display panel (PDP), X3 = -1 if the biotech
logo appears on the information panel (IP); and, X4= 1 if a logo is present and X4= -1 in
if there no logo. EDU ij denotes the education levels of the ith individual, where j = 1,2,
…6 for 6 education categories, and EDU ij = 1 if respondent ith indicated their education
level falls in the jth category, otherwise EDU ij = 0.
INC ij reflects the annual yearly
income of the ith individual, where j = 1,2, 3…9 for 9 income categories. INC ij = 1 if the
ith respondent indicated their income is in the jth category, otherwise INC ij = 0. RACE ij
represents the ethnic background of the ith individual, where j = 1,2, …6 for 6 ethnic
background. RACE ij = 1 if the ith respondent indicated their race is in the jth category,
otherwise, RACE ij = 0. AGE ij represents the age group of the i th individual, where j =
1,2, …6 for 6 ages groups, and AGE ij = 1 if ith respondent indicated their age is in the jth
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