Parc Mediterrani de la Tecnologia
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The impact of the sensory experience on scale and
preference heterogeneity: The GMNL model approach
applied to pig castration and meat quality case study
Zein Kallasa, Francesc Borrisser-Pairób, Beatriz Martínezc, Ceferina Vieirac, Begoña
Rubioc, Nuria Panellab, Marta Gilb, María Belén Linaresd, María Dolores Garridod, Alvaro
Olivarese; Miguel Ibáñeze; M. Angels Oliverb, José María Gila
a Centre
for Agro-food Economy and Development, Castelldefels, Barcelona.
Product Quality program, finca camps i armet, e-17121 Monells, Girona.
c Estación Tecnológica de la Carne, Instituto Tecnológico Agrario, Jta. de Castilla y León, Guijuelo.
d Facultad de Veterinaria, Tecnología de los alimentos, Universidad de Murcia, Murcia.
e Facultad de Veterinaria, Producción Animal, Universidad Complutense de Madrid, Madrid.
b IRTA-Monells,
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 ANIMAL WELFARE is becoming a relevant FACTOR affecting
CONSUMER PREFERENCES.
 Consumers are DEMANDING animals being reared, fed and
housed AS CLOSELY AS POSSIBLE as they would in their
NATURAL CONDITIONS.
 The growing CONCERNS about ANIMAL WELFARE in EU are
being extensively debated, resulting in CONTINUOUS CHANGES
in regulations and POLICIES.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 EU regulations have led to BANS of a number of INTENSIVE
farming methods.
 In this context, PIG WELFARE has received and is still receiving
special attention as pork is the MOST PRODUCED and
consumed meat in the EU.
 For instance, the Council Directive 2008/120/EC has BANNED
the use of SOW STALLS by January 2012.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 CASTRATION of ENTIRE MALES’ pigs is carried out:
 To ENCOURAGE the DEPOSIT OF FAT
 To PREVENT aggressive BEHAVIOR problems
 To AVOID the RISK of obtaining meat with BOAR TAINT
BOAR
TAINT
Off-odour and flavour related to the accumulation of
Androstenone and Skatole in the fat tissue
Consumers REACT DIFFERENTLY to this
SMELL and therefore it can affect
CONSUMERS’ ACCEPTABILITY of pork
There is an associated MEAT
4
(sensory) QUALITY problem
Trade-off
ANIMAL
WELFARE
MEAT
QUALITY
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 About 97.6 million pigs (79.3% of the total EU pig production) were
CASTRATED in 2008 in the EU, 48.7% of which were surgically
CASTRATED WITHOUT ANAESTHESIA
 Castration can be LEGALLY performed without anaesthetics during
the first SEVEN days after birth
 After that should only be performed under
ANAESTHESIA and must include a prolonged
ANALGESIA by a VETERINARIAN
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 Social CONCERN for ANIMAL WELFARE has increased: castration
carried out without anesthesia could have a NEGATIVE IMPACT.
 The EU is considering banning castration without anesthesia by
2018 and promoting the raising of entire males.
European Declaration on alternatives to
surgical castration of pigs
The European Commission and representatives of European pig farmers,
meat industry, traders, retailers, scientists and NGO’s committed
themselves to plan to voluntarily end surgical castration of pigs in Europe
by January 1st, 2018.
There are some exceptions
December 2010
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 Many alternatives to AVOID CASTRATION have been explored
 Genetic SELECTION and gender selection for ‘low-taint’ pigs
 Different MANAGEMENT and rearing strategies
 Slaughter at a YOUNGER age and lower weight
 DETECTION of boar taint at slaughter line
 MIXING of tainted with untainted meat
 MASKING
unpleasant
odours
and
flavours
with
the
appropriate masking strategy such as spices, marinades or
heat treatment.
 If the castration is applied, the IMMUNOCASTRATION
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Background
 Focusing only on the ACCEPTANCE of the most effective
masking strategy gives
only a
PARTIAL VIEW
OF THE
CONSUMERS’ PREFERENCES.
 Liking or disliking a food product does not only depend on
PHYSICOCHEMICAL PROPERTIES but also on the consumers'
EXPECTATIONS and attitudes toward EXTRINSIC cues.
 The consumer FINAL CHOICE of a food product is a MIXTURE
between the SENSORY EXPERIENCE (Intrinsic cues) and the
other descriptors of the products (Extrinsic cues).
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
1. INTRODUCTION: Objective
 Thus, the objective of this paper is threefold:
1. First, to analyze the CONSUMERS’ EXPECTED PREFERENCE
toward a MASKING STRATEGY of frankfurter sausages.
2. Second,
to
study
THE
IMPACT
OF
THE
SENSORY
EXPERIENCE of this masking strategy on such preferences.
3. Third, to assess how the NON-OBSERVED HETEROGENEITY
both at the SCALE AND MEAN PREFERENCES of the
sausage’ attributes are AFFECTED BY THE EXPERIENCE in a
REAL SHOPPING SCENARIO.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK
 We applied TWO NON-HYPOTHETICAL DISCRETE CHOICE
EXPERIMENTS (DCE) by creating a REAL SHOPPING SCENARIO
BEFORE and AFTER a HEDONIC SENSORY TEST for frankfurter
sausage.
 To motivate the consumers in the RECRUITMENT process, they
were REWARDED by €15.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK: Steps
1. First,
participants
QUESTIONNAIRE
were
their
asked
to
ATTITUDES
answer
and
in
a
SHORT
CONSUMPTION
behaviour towards pork meat and pork frankfurter sausage in
particular. SOCIOECONOMIC and LIFE-STYLE variables were
also collected
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK: Steps
2. Second, participants were UNEXPECTEDLY REWARDED by an
extra €5 and asked to select THEIR PREFERRED FRANKFURTER
SAUSAGE from different choice sets built within the DCE design.
Consumers were warned that their selection will have a
consequence as a REAL MARKET WILL BE CREATED at the end
of the experiment to exchange real money and real products.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK: Steps
3. Third, a HEDONIC EVALUATION test was carried out to assess
the impact of the chosen masking strategy for boar taint and to
CREATE A CURRENT SENSORY EXPERIENCE of the analysed
product. Participants tasted FOUR DIFFERENT FRANKFURTER
SAUSAGES with two different treatments: if the meat is obtained
from CASTRATED pig or BOARS and if the FLAVOUR is
ORIGINAL or with the masking strategy.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK: Steps
4. Fourth, consumers were INFORMED ABOUT WHICH TYPE of
sausages they tasted in order to ASSOCIATE their sensory
EXPERIENCE with the SPECIFIC products and characteristics.
Then, the SAME DCE WAS REPEATED and consumers turned to
reselect their preferred products from the same choice sets and
asked to take into consideration their sensory experience.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK: Steps
5. Fifth, a REAL MARKET WAS CREATED to exchange real product
and money. Consumers who accepted to participate were
OBLIGED TO PURCHASE their chosen product from a randomly
selected choice set..
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
2. METHODOLOGICAL FRAMEWORK: Data
 150 consumers selected from the Madrid province who regularly
PURCHASE food and having PURCHASED AND CONSUMED
FRANKFURTER sausage at least ONE TIME in the last MONTH
Sociodemographic
variables
(N)
48.7
Primary
12.0
Family Income (€/month)
(146)
Secondary University
40.0
48.0
<1,500
42.5
10.7%
24.0%
2.0%
150
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Self-employed
time
28.7%
11.0
full-time
Employee Parttime
15.3%
46.6
Self-employed
unemployed
6.0%
1,500-3,000 >3,000
part-time
Student
5.3%
Employee full
Retired
N
41.5
Study level
(150)
Housewife
Employment
situation
(150)
Age
Gender
(150)
(150)
(years) % female
8.0%
3. EMPIRICAL APPLICATION: The DCE: Attributes and levels
 Based on the literature and discussion groups we identified the
following attributes and levels:
 FLAVOUR: original and the masking strategy with spices and
naturally smoked.
 CASTRATION: meat obtained from castrated pigs or boars.
 BRAND TYPE: manufacturer and private brands.
 PRICE: €1.79, €1.39, €0.99, €0.59.
 We consider ceteris paribus some attributes for all the offered
alternative products (same package, same appearance, same
sausage size, same format, same shelf life, same origin and same
Paper prepared
for presentation at the EAAE-AAEA Joint Seminar
production method
technology
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Design
 We followed the DUAL RESPONSE CHOICE EXPERIMENT design.
 From the FULL FACTORIAL DESIGN using the total number of
attributes and levels which led to a total of 32 (23x41) hypothetical
products. In a choice set of 4 alternatives we have (23x41)4
possible combinations.
 The orthogonal fractional factorial design with only 8 CHOICE
SETS.
 Participants were also asked to perform an additional task (HOLDOUT TASK) to conduct validity tests which is single-choice set
with eight different sausages to those provided in the main task
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Design
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Design
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Real market
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Econometric model
U jn  V jn ( X j , Sn )   jn
 The basic model is THE MULTINOMIAL LOGIT MODEL (MNL).
U njt   xnjt   njt  n
n  1, , N
j  1, , J
t  1, , T
 It imposes homogeneity in preferences for observed attribute
 The IIA property seldom hold.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Econometric model
 The Mixed Logit Model (MIXL)
U njt   n xnjt   njt  n n  1, , N j  1, , J t  1, , T
 Extend the MNL introducing for unobserved heterogeneity by
allowing random coefficients on attributes .
 Recent
studies
argued
that
much
of
the
PREFERENCE
HETEROGENEITY captured by random parameters in MIXL can be
better captured by the scale term; and thus known as “SCALE
HETEROGENEITY”.
 The MIXL turns to be likely a POOR APPROXIMATION to stated
data if scale heterogeneity
is not accounted
Paper prepared for presentation
at the EAAE-AAEAfor
Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
3. EMPIRICAL APPLICATION: The DCE: Econometric model

The Generalized Multinomial Logit Model (GMNL)
U njt  [ n   γn  (1  γ) nn ] X njt   njt
 Known also as Generalized Mixed Logit Model (G-MXL).
 n is a scaling factor that proportionately scales the  up or down
for each individual n.
  is a mixing parameter, and its value determines the level of
mixing or interaction between the scale heterogeneity coefficient
and the parameter heterogeneity coefficient .
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
4. RESULTS: Sensory results
 Creating the Sensory Experience
Odour
Flavour
Overall
acceptability
Original sausage from boar meat
5.40c (1.43)
5.62c (1.56)
5.46c (1.61)
Flavoured1 sausage from boar meat
6.51a (1.27)
6.36b (1.26)
6.42a (1.18)
Original sausage from castrated meat
5.69b (1.19)
6.20b (1.33)
5.91b (1.30)
Flavoured1 sausage from castrated meat
6.62ª (1.16)
6.69a (1.18)
6.62a (1.29)
Type of pork meat
 The FLAVOURED SAUSAGE obtained from castrated and boar meat
had the HIGHEST ACCEPTABILITY scores than the remaining type
of sausage. This confirms that the APPLIED MASKING STRATEGY
had a POSITIVE
EFFECT
frankfurter
sausage
Paper
prepared foron
presentation
at the EAAE-AAEA
JointACCEPTANCE.
Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a
-0.26***a
Flavoured1
-0.47**b
0.50**a
Non-Random Parameters in utility functions ()
Price
-1.69***
-1.51***
Opt-Out
-0.40***
0.02
Diagonal values in Cholesky matrix
Non-castrated animal
1.20***
1.04***
Private brand
0.04
0.46**
Flavoured
0.28
0.70***
Covariances of the Random parameters
Private Brand : Non-castrated animal
-0.11
-0.01
Flavoured : Non-castrated animal
-0.20
-0.07
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
Std. Dev. Non-castrated animal
1.20***
1.04***
 The POSITIVE/NEGATIVE
sign
of
the
coefficient
Std. Dev. Private brand
0.10
0.47*** implies
Std. Dev. Other Spanish origin
1.19***
1.25***
HIGHER/LOWER
levels
of
UTILITY
associated
with
these
attributes’
Log-Likelihood (θ)
-1,529.54
-1,418.39
Log-Likelihood (0)
-1,931.32
-1,931.32
levels
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a
-0.26***a
Flavoured1
-0.47**b
0.50**a
Non-Random Parameters in utility functions ()
Price
-1.69***
-1.51***
Opt-Out
-0.40***
0.02
Diagonal values in Cholesky matrix
Non-castrated animal
1.20***
1.04***
Private brand
0.04
0.46**
Flavoured
0.28
0.70***
Covariances of the Random parameters
Private Brand : Non-castrated animal
-0.11
-0.01
Flavoured : Non-castrated animal
-0.20
-0.07
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
 BEFORE
THE HEDONIC VALUATION
EXPERIENCE,
consumers
Standard deviations of parameters distribution
Std. Dev. Non-castrated animal
1.20***
1.04***
exhibit a preference
for
meat
obtained
from
PIGS
REARED
IN
Std. Dev. Private brand
0.10
0.47***
Std. Dev. Other Spanish origin
1.19***
1.25***
NATURAL CONDITION
(i.e.
non
castrated)
as
a
potential
preference
Log-Likelihood (θ)
-1,529.54
-1,418.39
Log-Likelihood (0)
-1,931.32
-1,931.32
for a positive pig
welfare
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a
-0.26***a
Flavoured1
-0.47**b
0.50**a
Non-Random Parameters in utility functions ()
Price
-1.69***
-1.51***
Opt-Out
-0.40***
0.02a
Diagonal values in Cholesky matrix
Non-castrated animal
1.20***
1.04***
Private brand
0.04
0.46**
Flavoured
0.28
0.70***
Covariances of the Random parameters
Private Brand : Non-castrated animal
-0.11
-0.01
Flavoured : Non-castrated animal
-0.20
-0.07
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
 However,
AFTER
TESTING
the 1.20***
different sausage1.04***
products,
Std. Dev. Non-castrated animal
Std. Dev. Private brand
0.10
0.47***
consumers
were
AWARE
OF
THE
IMPORTANCE
OF
CASTRATION
Std. Dev. Other Spanish origin
1.19***
1.25***
Log-Likelihood (θ)
-1,529.54
-1,418.39
on meat quality
but
not
statistically
significant.
Log-Likelihood (0)
-1,931.32
-1,931.32
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a
-0.26***a
Flavoured1
-0.47**b
0.50**a
Non-Random Parameters in utility functions ()
Price
-1.69***
-1.51***
Opt-Out
-0.40***
0.02
Diagonal values in Cholesky matrix
Non-castrated animal
1.20***
1.04***
Private brand
0.04
0.46**
Flavoured
0.28
0.70***
Covariances of the Random parameters
Private Brand : Non-castrated animal
-0.11
-0.01
Flavoured : Non-castrated animal
-0.20
-0.07
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
 For the
BRAND
ATTRIBUTE
preference,
consumers1.04***
showed a
Std. Dev. Non-castrated animal
1.20***
Std. Dev. Private brand
0.10
0.47***
rejection
of
private
brands
with
NON-SIGNIFICANT
DIFFERENCES
Std. Dev. Other Spanish origin
1.19***
1.25***
Log-Likelihood (θ)
-1,529.54
-1,418.39
BEFORE and AFTER
the
hedonic
test
Log-Likelihood (0)
-1,931.32
-1,931.32
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a
-0.26***a
Flavoured1
-0.47**b
0.50**a
Non-Random Parameters in utility functions ()
Price
-1.69***
-1.51***
Opt-Out
-0.40***
0.02
Diagonal values in Cholesky matrix
Non-castrated animal
1.20***
1.04***
Private brand
0.04
0.46**
Flavoured
0.28
0.70***
Covariances of the Random parameters
Private Brand : Non-castrated animal
-0.11
-0.01
Flavoured : Non-castrated animal
-0.20
-0.07
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
 Focusing
on
the
FLAVOUR
ATTRIBUTE,
consumers before
testing
Std. Dev. Non-castrated animal
1.20***
1.04***
Std. Dev. Private brand
0.10
0.47***
the products
showed
a
NEGATIVE
EXPECTED
PREFERENCE.
Std. Dev. Other Spanish origin
1.19***
1.25***
(θ)
-1,529.54
However, afterLog-Likelihood
the testing
their utility
become positive-1,418.39
with highly
Log-Likelihood (0)
-1,931.32
-1,931.32
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
significant difference
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a PARAMETER) that
-0.01b captures
 Interpreting the tau
parameter (KEY
Private Brand
-0.21***a
-0.26***a
Flavoured1
-0.47**b showed a substantial
0.50**a
the SCALE HETEROGENEITY,
results
scale
Non-Random Parameters in utility functions ()
Price in the pre
-1.69***
-1.51***
heterogeneity in the data
sensory and a non-significant
Opt-Out
-0.40***
0.02
Diagonal values in Cholesky matrix
value in the post experiment.
Non-castrated animal
1.20***
1.04***
Private
brand
 After the sensory
experience
the 0.04
VARIATION OF THE0.46**
DEGREE of
Flavoured
0.28
0.70***
Covariances
of the
Random their
parameters
RANDOMNESS in their final decision
and
hence
degree of
Private Brand : Non-castrated animal
-0.11
-0.01
Flavoured : Non-castrated
animal
-0.20
-0.07
UNCERTAINTY
DECREASED
significantly.
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
Std. Dev. Non-castrated animal
1.20***
1.04***
Std. Dev. Private brand
0.10
0.47***
Std. Dev. Other Spanish origin
1.19***
1.25***
Log-Likelihood (θ)
-1,529.54
-1,418.39
Log-Likelihood (0)
-1,931.32
-1,931.32
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a TASTE
-0.26***a
 Regarding
the
UNOBSERVED
(PREFERENCE)
Flavoured1
-0.47**b
0.50**a
Non-Random
Parameters
in utility
functions ()
HETEROGENEITY, it is captured
by the
standard
deviation
of the
Price
-1.69***
-1.51***
-0.40***
0.02
random parameters.Opt-Out
Diagonal values in Cholesky matrix
Non-castrated
animal showed1.20***
1.04***
 The estimated
models
STATISTICALLY SIGNIFICANT
Private brand
0.04
0.46**
Flavoured
RESULTS with the
exception of0.28
the private brand0.70***
in the pre
Covariances of the Random parameters
Private
Brand : Non-castrated animal
-0.11
-0.01
sensory.
Flavoured : Non-castrated animal
-0.20
-0.07
Flavoured : Private brand
0.07
-0.48*
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
Std. Dev. Non-castrated animal
1.20***
1.04***
Std. Dev. Private brand
0.10
0.47***
Std. Dev. Other Spanish origin
1.19***
1.25***
Log-Likelihood (θ)
-1,529.54
-1,418.39
Log-Likelihood (0)
-1,931.32
-1,931.32
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Pre sensory
Post sensory
Random Parameters in utility functions ()
 The main MOTIVATION
OF
THE
G-MNL
model is to SEPARATE
the
Boar animal
0.28**a
-0.01b
Private Brand
-0.21***a
-0.26***a
estimation of SCALE
heterogeneity
from
TASTE
heterogeneity,
Flavoured1
-0.47**b
0.50**a
Non-Random Parameters in utility functions ()
identified by the gamma parameter.
Price
-1.69***
-1.51***
Opt-Outis RELATIVELY
-0.40***
0.02
 GAMMA in both model
far from ZERO.
Which
Diagonal values in Cholesky matrix
animal
1.20*** to be INDEPENDENT.
1.04***
implies thatNon-castrated
both heterogeneity
tend
This
Private brand
0.04
0.46**
0.28 POST EXPERIMENT.
0.70***Gamma
INDEPENDENCE is Flavoured
emphasized in the
Covariances of the Random parameters
Private Brand :from
Non-castrated
animal
-0.11 both types of heterogeneity
-0.01
increased
0.41 to
0.72 and thus
Flavoured : Non-castrated animal
-0.20
-0.07
Private brand
0.07
-0.48*
becomesFlavoured
MORE: INDEPENDENTLY
identified
scale parameters
Variance parameter tau in scale parameter
1.10***
0.01
Weighting parameter Gamma
0.41***
0.72***
Standard deviations of parameters distribution
Std. Dev. Non-castrated animal
1.20***
1.04***
Std. Dev. Private brand
0.10
0.47***
Std. Dev. Other Spanish origin
1.19***
1.25***
Log-Likelihood (θ)
-1,529.54
-1,418.39
Log-Likelihood (0)
-1,931.32
-1,931.32
LL ratio test
803.55 (0.000)
1,025.87 (0.000)
2
Pseudo R
0.208
0.265
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
AIC/N
2.576
2.391
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
5. CONCLUSIONS
 The SENSORY EXPERIENCE for the different frankfurter sausages
with the main identified STRATEGY of masking BOAR TAINT, have
had
impact
ON
BOTH
THE
SCALE
AND
PREFERENCE
HETEROGENEITY by affecting the TAU and the GAMMA mixing
estimates of the scale parameter.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
5. CONCLUSIONS
 The HEDONIC TEST DECREASED the degree of RANDOMNESS
and UNCERTAINTY of consumers in their final election and the
SOURCE of UNOBSERVED HETEROGENEITY obtained from the
scale BECOME MORE INDEPENDENT than the taste preference.
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
5. CONCLUSIONS
 These results HIGHLIGHT the IMPORTANCE of the DIRECT
PROMOTION and the in situ MARKETING TECHNIQUES of these
types of product in the retail point by GIVING POTENTIAL
CONSUMERS THE OPPORTUNITY to test the product.
 More studies ARE NEEDED to be done, especially to analyze the
IMPACT of SENSORY experience on the attributes NON-
ATTENDANCE and on the INTERNAL and EXTERNAL VALIDITY of
choices
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy
Thank you for your
attention
Paper prepared for presentation at the EAAE-AAEA Joint Seminar
“Consumer Behavior in a Changing World: Food, Culture, Society”. March 25 to 27, 2015. Naples, Italy