Consumers’ preferences for Iberian dry-cured ham and the influence of mast feeding: An application of conjoint analysis in Spain

Meat Science 83 (2009) 684–690

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Meat Science journal homepage: www.elsevier.com/locate/meatsci

Consumers’ preferences for Iberian dry-cured ham and the influence of mast feeding: An application of conjoint analysis in Spain Francisco J. Mesías *, Paula Gaspar, Ángel F. Pulido, Miguel Escribano, Francisco Pulido Escuela de Ingenierías Agrarias, Universidad de Extremadura, Ctra. Cáceres, s/n, 06071 Badajoz, Spain

a r t i c l e

i n f o

Article history: Received 8 June 2009 Received in revised form 23 July 2009 Accepted 1 August 2009

Keywords: Iberian ham Consumers’ preferences Segmentation

a b s t r a c t This paper analyzes consumers’ preferences for Iberian dry-cured ham, one of the most typical and highly prized meat products in Spain. The data were obtained by a survey carried out between April and May 2006 with a sample of 417 consumers in Extremadura (SW Spain). Conjoint Analysis was used to estimate the relative importance of the main attributes affecting preferences for Iberian ham and to create consumer segments with similar preference profiles. Results have shown that Price and Type of ham are the most important attributes for the choice of ham. Simulation analyses determined the surcharge that consumers are willing to pay for an Iberian mast-fed ham instead of an Iberian ham, thus identifying an ideal cluster for Iberian mast-fed ham. Ó 2009 Elsevier Ltd. All rights reserved.

1. Introduction For a long time, dry-cured ham has been a traditional and highly appreciated food product in many countries. Spain leads the production and consumption of this product, with over 36 million pieces produced in 2004 (Cruz, 2005) and an annual consumption of 4.6 kg per person (MAMAMAPA, 2007). In Spain, two main types of dry-cured ham are found: Serrano ham, which is made with white pigs that are not usually fed a special diet, and Iberian ham, which is made with an indigenous breed of pig (Iberian pig) native to the southwestern portion of the Iberian peninsula.1 Iberian pigs (whose ancestor is the Sus Mediterraneus) are described as having thin extremities, curved backs, and long snouts. These characteristics have developed over generations and have allowed the Iberian pig to adapt to the Mediterranean woods (dehesas2) where they typically graze freely and must walk long distances for nourishment. It is mainly the feeding of the animals that determines the different qualities of Iberian hams. Higher quality ham comes from Iberian pigs bred extensively in dehesa habitats, feeding primarily on acorns and pastures. In this natural environment Ibe* Corresponding author. E-mail address: [email protected] (F.J. Mesías). 1 The term White pig or White pig breeds, commonly used in Spain, refers to all the improved pig breeds such as Large white or Landrace. The term White ham is used the same way. 2 Dehesa is the Spanish name for the typical rangelands that predominate in the western and southern lowlands of the Iberian Peninsula. These rangelands are used for livestock range farming and are characterized by its mix of pasture and evergreen oak stands. Usually mixed-species grazing of beef cattle, sheep, and Iberian pigs is practiced: while the ruminants make use of the pasture, stubble, and fallow land, Iberian pigs in their final phase of fattening for market feed free range on the pasture and on acorns. 0309-1740/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2009.08.004

rian pig develops an infiltrated coat of fat among the muscles giving the meat a very particular flavour. Scarcity of dehesa lands, together with variability in the acorn harvest, limit the number of pigs allowed to feed on acorn diets. In other cases, and due to market demands, such as price, animals are fed with other products, mainly cereals. The result is the existence of three categories or qualities of pigs that produce Iberian ham (European Commission., 2006): 1. ‘‘Bellota” (mast-fed): Pigs are bred extensively and nourished in ‘‘montanera”, i.e., in a traditional method in which animals are free to roam in the dehesa countryside and have mainly eaten acorns and pasture. 2. ‘‘Recebo”: Pigs that spend some time in ‘‘montanera” and then finish their fattening stage with fodder. 3. ‘‘Cebo” (fodder): Pigs bred intensively and fed on a grain-based diet. 4. Both recebo and cebo Iberian ham are known in the market just as Iberian ham, to differentiate them from the higher quality Iberian mast-fed ham. Although Iberian ham is a greatly appreciated product, reaching high prices in the market, its marketing is influenced by the wide variety of Iberian hams offered (depending on the production system, degree of purity used in the Iberian breed, different types of feeding regime, etc.) which sometimes generate distrust in the consumer and lead to a lack of loyalty towards the product. Many studies have been conducted in recent years trying to improve the aforementioned constraints, but they have mainly focused on the manufacturing technology and on improvement of production processes (Andrés et al., 2001; Cava, Ventanas, Ruiz,

F.J. Mesías et al. / Meat Science 83 (2009) 684–690

Andrés, & Antequera, 2000). Sensory assessment of Iberian ham using trained panelists has also been widely studied (Andrés, Cava, Ventanas, Thovar, & Ruiz, 2004; Ruiz, Ventanas, Cava, Timón, & García, 1998), but there is a lack of studies dealing with consumers’ preferences and attitudes regarding Iberian ham, or its value compared with other cured hams. Thus, research into consumer preferences towards Iberian hams compared with other types of cured hams that are their competitors in the market is of interest. In this context, it is necessary to identify the issues that are important for the consumers, using market research tools to quantify the relative importance of each of these aspects for Iberian dry-cured ham purchasing and consumption. Among the different methods that can be used to achieve these objectives, Conjoint Analysis is one of the most interesting and widely used in the food market (Martínez-Carrasco, Brugarolas, Del Campo, & Martínez, 2006; Murphy, Cowan, & Henchion, 2000; Ness & Gerhardy, 1994; Souza & Lucas, 2001). It allows one to estimate the relative importance of different attributes which constitute the structure of consumer preferences. Also, the existence of consumer segments with similar preferences can be determined. The aim of this study was to determine the structure of consumer preferences for Iberian ham, differentiating between mast-fed and fodder-fed hams, and comparing them with Serrano dry-cured ham which is their main competitor. This preference function was then used within a cluster analysis to create consumer segments with similar preference profiles. Finally, a simulation analysis was carried out to determine the increase in price that consumers are willing to pay for an Iberian mast-fed ham instead of another Iberian ham. This is considered to be a very important issue, as the rearing of Iberian mast-fed pigs is far more expensive (management of the pigs in the dehesa rangeland, mast cost, added time to grow and reach slaughter weight, etc.) than that of Iberian pigs (mostly fed with fodder). Whether the consumers are willing to pay this difference in price or not is of great interest for the producers as it will help them get information about their ideal consumer segments. 2. Materials and methodology The data were obtained by interviewing a representative sample of regular Iberian ham consumers in the region of Extremadura (SW Spain). Respondents had to be primarily responsible for food shopping within the household. The survey was carried out between April and May 2006. The design was random stratified sampling weighted in proportion to the population of each city. The criterion which was adopted, mainly due to budget restrictions, was to only take into consideration population centres of more than 3000 inhabitants (which represent more than 75% of the total population of the region). In every town, households were selected through a random computerized procedure, in which each household had the same probability to be selected. Surveyors were instructed to interview those members of the selected households responsible for food shopping. In case of refusal, replacement households were drawn and interviewed. Although 480 interviews were handed out, 63 had to be discarded for a variety of reasons (mainly incomplete response). The maximum error was 4.89% for a 95% confidence level (k = 2). Conjoint Analysis is a multivariate research technique that starts from the assumption that purchasing behavior can be interpreted as a choice among different products or brands which possess a set of differentiating attributes or characteristics (Varela, Braña, & Rial, 1997). According to Ness and Gerhardy (1994), the main assumptions in the Conjoint model are: (i) alternative products can be defined by a series of specific levels of a common set of attributes; and (ii) a product’s total utility to a consumer is given by the partial utilities (part-worths) of each attribute level. The purpose of Conjoint Analysis would be to individualize those com-

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binations of attributes that give the consumer the greatest utility, and to determine the relative importance of each attribute in terms of its contribution to the total utility. Two important aspects of the model that need to be specified prior to carrying out the estimation are the choice of the composition rule and the relationship between the utilities. The composition rule adopted in this study is additive, as according to Hair, Anderson, Tatham, and Black (1999) it is the one that takes into account most (80% or 90%) of the variation of the preference in almost all cases and is thus sufficient for most applications.3 Concerning the relationship between the utilities, a linear-less model was used for the attribute price, as, in general terms, higher prices correspond to lower utilities or preferences (Gil & Sánchez, 1997; Kupiec & Revell, 2001; Souza & Lucas, 2001). For the rest of the attributes (qualitative) a part-worth model was used, which implies no defined relationship between the different levels of the attributes and their par-worths. This model is the most general and flexible and is frequently used for qualitative attributes (Green & Srinivasan, 1978; Hair et al., 1999). 2.1. Selection and definition of attributes and levels The subsequent step in the research design concerns the identification of appropriate attributes and, subsequently, the specification of feasible attribute levels (Hair et al., 1999). These attributes must show the product’s characteristics and dimensions most important for consumers (Cattin & Wittink, 1982). Several studies carried out using conjoint analysis for meat and meat products have used both intrinsic attributes (colour, tenderness, fat content) (Cunhal-sendim, Albiac, Delfa, & Lahoz, 1999) and extrinsic attributes (price, place of purchase, brand, quality label) (Cheng, Clarke, & Heymann, 1990; Gillespie, Taylor, Schupp, & Wirth, 1998; Huang & Fu, 1995; Steenkamp, 1987), as well as a mixture of the two (Grunert, 1997; Sánchez, Goñi, Marañón, & Martín, 2000). The choice of those attributes is the result of both previous qualitative research (Cunhal-Sendim et al., 1999; Grunert, 1997) and bibliographical revision and subsequent selection by the research team (Huang & Fu, 1995; Sánchez, Sanjuán, & Akl, 2001). The specificity of the Iberian ham sector led to the decision to use a three-step mixed tool for the selection of the attributes and their levels. (1) A list of attributes was drawn up from a review of studies on consumer preferences for ham and meat products (Mesías, Martínez-Carrasco, & Albisu, 1997; Steenkamp, 1987; Sánchez et al., 2000; Sánchez et al., 2001). (2) These attributes were subjected to a preliminary evaluation by 25 consumers, who were asked to rate them according to their importance in the purchasing decision, and to indicate the levels that they considered feasible. (3) Finally, the most highly valued attributes and their levels were presented to a panel of dry-cured ham experts, who chose the four they considered most influential in the Iberian ham purchasing decisions. They also selected the definitive levels. Table 1 lists the attributes and the levels finally used in the study. 2.2. Creation of the stimuli to be evaluated by the surveyees Once the factors and their levels were selected, the stimuli (combinations of different levels of the attributes) that would be P P Analytically, the additive composition rule is the following: Y ¼ ni¼j X ij m j¼1 V ij , where Y is the total utility, Vij is the utility associated with level j (j = 1, 2..., m) of attribute i (i = 1, 2..., n) and Xij is a dummy variable that takes the value of 1 (or 0) in the case of presence (or absence) of the jth level of the ith attribute. 3

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presented to the consumers in the survey were determined. In the present study, the number of potential stimuli was 72 (3  2  4  3). To show all these stimuli to the consumers would not be feasible due to the time needed and because of the difficulty in getting consistent and significative answers for too many products. It was therefore necessary to use what is known as a fractional factorial design to reduce the number of profiles to be judged by the respondents. Using Conjoint Designer software the final number of products to be presented was reduced to 10. Their descriptions are given in Table 2. 2.3. Data collection Once the products have been defined, the respondents had to evaluate them. This was done by presenting the respondents with a specific written description of each product to be evaluated. Consumers were requested to rate them from 1 (very low preference) to 9 (very high preference). Although ranking reveals with more intensity the differences between the levels of the attributes, the utility model developed with ratings provides a more accurate view of the consumers´ preferences (Sayadi, Gonzalez, & Calatrava, 2005). This, together with the increasing difficulty for the consumers to handle the ranking procedure led to the use of ratings in this study. 3. Results and discussion The model was estimated using ordinary least squares regression analysis, the most common methodology (Ruiz & Munuera, 1993; Wittink & Cattin, 1989). The estimated model establishes the relative importance of the attributes, as well as the part-worth of each level of the attributes. One of the main results of the model is the estimate of a utility function (formed by the combination of the part-worths of the different levels) for each of the respondents. The accuracy of the estimation was tested by calculating the Pearson Correlation Coefficient between the original ratings given by the respondents and those determined by the model. The high value of this coefficient (0.933) indicates that the model provides good prediction of the consumers’ preferences. Table 3 shows the aggregate results for the whole sample. A positive sign in the value of a level’s part-worth indicates that, for this survey, the presence of that level of the attribute adds that amount of utility to the product (for two levels with positive signs, that of greater value is the one that provides greater utility). A negative sign, on the other hand, implies that the presence of that level of the attribute in the product lessens its utility. It is seen that, as the price increases, the utility for the consumer decreases. This conforms with various Conjoint Analysis studies of food products, such as those of Murphy et al. (2000), Gil and Sanchez (1997) and Mesías, Escribano, Rodríguez de Ledesma, and Pulido (2005). Table 1 Attributes and levels selected for the Conjoint Analysis. Attributes

Levels

Type of ham

Iberian mast-fed Iberian Serrano With Without 6 €/kg 16 €/kg 26 €/kg 36 €/kg Sliced and packed Over the counter Whole ham

Designation of Origin Price

Pruchasing format

The maximum utility, obtained from the combination of the greatest part-worths of each attribute, would give the ideal product: Iberian mast-fed ham, with Designation of Origin (DO), with a price of 6 €/kg and bought as a whole ham. 3.1. Segmentation Having determined the preferences from the utilities estimated in the Conjoint Analysis, a cluster analysis was then applied to classify the consumers into homogeneous preference groups. The calculations were performed with the Cluster unit of the SPSS 15 software, using the k-means cluster procedure.4 The inputs used were the coefficients of each respondent’s utility function. A 3-cluster solution was chosen as being in accord with the size of the segments, and as giving the highest statistical significance. An analysis of variance (ANOVA) showed that all the segments differed significantly (p < 0.001) from each other with respect to the utility variables generated by the Conjoint Analysis and which had been used to determine the segmentation. The mean partworths and their relative importance were then calculated for each of the levels of the attributes. These results, together with the size of each cluster, are listed in Table 4. Cluster 1 is the smallest group, including only 26.5% of the respondents. This cluster is similar in some aspects to Cluster 3, for example in the importance their consumers grant to the Type of ham or to the DO. However, Price is given more importance within Cluster 1 than in Cluster 3, and in fact, this is the most important attribute for Cluster 1. The greatest difference between Clusters 1 and 3 was for purchasing format, whereby Cluster 1 prefers purchasing hams over the counter and Cluster 3 prefers whole ham. Cluster 2, with 28% of consumers, is the one of the three clusters that gives the lowest importance to the Type of ham and the DO, and the highest importance to the Purchasing format and the Price. Specifically, while the consumers in Cluster 2 attached increased utilities to price increase, the other two clusters granted decreasing utilities to price increase. Although some authors (Sánchez et al., 2000) have detected the use of price as a signal of the product’s quality, with utility growing as the price increases, this is an exceptional finding in the food market. Finally, it is noteworthy that the importance given to the Purchasing format is more than three times as big as the figures found in the other clusters. Table 5 lists the detailed socio-demographic characteristics and ham consumption habits of the clusters and of the overall sample. It also shows the level of significance obtained in a Chi-Square test carried out for the three clusters. The analysis of Table 5 complements the description of the clusters. It is worth mentioning that the consumers from Cluster 2 show the highest appreciation for the Designation of Origin compared to Clusters 1 and 3. Consequently, they are also willing, to a higher degree, to pay extra for this quality attribute. These particular data disagree with those shown in Table 4, where Cluster 2 gives the lowest relative importance to Designation of Origin of the three clusters. This may be due to the fact that, in the Conjoint Analysis questionnaire, consumers could not separate the attributes that determined the final product. 4 Cluster analysis, also called segmentation analysis, seeks to identify homogeneous subgroups of cases in a population (clusters). Cluster analysis implements this by seeking to identify a set of groups which both minimize within-group variation and maximize between-group variation. The main general approaches to cluster analysis are: (i) Hierarchical clustering: the algorithm starts creating as many clusters as cases and then determines how many clusters best suit the data. It is an appropriate technique for smaller samples (typically < 250). (ii) k-means clustering: the analyst has to specify the number of clusters in advance, and then the algorithm calculates how to assign cases to the K clusters. k-means clustering is much less computer-intensive and is therefore preferred when datasets are large (>250).

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F.J. Mesías et al. / Meat Science 83 (2009) 684–690 Table 2 Final profiles presented to surveyees for evaluation. Product

Type of ham

Designation of Origin

Price (€/kg)

Purchasing format

1 2 3 4 5 6 7 8 9 10

Iberian Serrano Iberian Iberian mast-fed Iberian mast-fed Serrano Iberian Iberian mast-fed Iberian Serrano

Without Without With Without With With Without Without With With

16 16 26 26 36 6 16 36 26 16

Over the counter Sliced and packed Over the counter Whole ham Sliced and packed Over the counter Sliced and packed Over the counter Sliced and packed Whole ham

Table 3 Aggregate results of Conjoint Analysis for the overall sample: relative importance of attributes and part-worths per level and atttribute. Attribute Type of ham Designation of origin

Price

Purchasing format

Level

Part-wortha

Relative importance (%)

Iberian mast-fed Iberian Serrano With Without 6 €/kg 16 €/kg 26 €/kg 36 €/kg Sliced and packed Over the counter Whole ham

1.138 0.152 1.920 0.347 0.347 0.431 1.149 1.867 2.585 0.160 0.010 0.150

43.5

12.4 38.5

5.6

a Part-worth refers to the partial utility of each attribute level. A positive (negative) sign in the value of a level’s part-worth indicates that the presence of that level of the attribute adds (lessens) that amount of utility to the product.

Table 4 Results of Conjoint Analysis by cluster: relative importance of attributes and part-worths per level and atttribute. Attributes and levels

Mean part-worthsa and relative importance Cluster 1 (107 ind.)

Cluster 2 (113 ind.)

Cluster 3 (183 ind.)

Type of ham Iberian mast-fed Iberian Serrano Relative importance

3.194 0.418 2.776 38.03%

0.742 0.684 0.058 25.54%

1.107 0.163 1.270 41.43%

Designation of Origin With Without Relative importance

0.839 0.839 10.69%

0.052 0.052 1.85%

0.306 0.306 10.65%

Price 6 €/kg 16 €/kg 26 €/kg 36 €/kg Relative importanceb

1.4142 3.7712 6.1282 8.4852 45.04%

0.545 1.453 2.361 3.269 48.79%

0.466 1.242 2.012 2.794 40.59%

Purchasing format Sliced and packed Over the counter Whole ham Relative importance

0.283 0.348 0.631 6.24%

0.544 0.244 0.787 23.83%

0.195 0.030 0.226 7.34%

a Part-worth refers to the partial utility of each attribute level. A positive (negative) sign in the value of a level’s part-worth indicates that the presence of that level of the attribute adds (lessens) that amount of utility to the product. b The apparent discrepancy between the percentage of relative importance for Price in Table 3 (38.5%) and the percentage of relative importance for Price by clusters shown in Table 4, is easily explained considering the behavior of Cluster 2: this cluster shows positive utilities for increasing prices as opposed to the other two groups. When the mean value of relative importance for Price is calculated for the overall sample, it becomes smaller than the original values by cluster.

3.2. Simulation analysis Simulation analysis implies the estimation of market shares for different real or hypothetical products in various competitive scenarios of interest. In this case we used the simulation analysis to quantify in monetary terms two levels of the attribute Type: Iberian mast-fed vs. Iberian.

The process of simulation involves the use of either a maximum utility model or a probability model as rules in predicting the choice of a stimulus. As the probability model poses certain problems when used for Conjoint Analysis, such as when it has to handle negative utilities (it would take them to be negative probabilities) it was decided to use the maximum utility model in the simulation.

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Table 5 Descriptions of clusters and general sample by socio-demographic characteristics and ham consumption habits (%) together with level of significance obtained by Chi-Square test. Variable

Cluster 1

Cluster 2

Cluster 3

Total

Significancea

Sex Man Woman

42.1 57.9

45.1 54.9

47.0 53.0

45.2 54.8

n.s.

Level of studies No formal education Primary education High school University

6.5 19.6 29.9 43.9

4.4 28.3 28.3 38.9

5.5 23.5 30.1 41.0

5.5 23.8 29.5 41.2

n.s.

Age of the respondent 18–35 years 36–50 years 51–65 years >65 years

32.1 36.8 17.0 14.2

31.0 28.3 27.4 13.3

31.1 30.6 25.1 13.1

31.5 31.5 23.6 13.4

n.s.

Residence Rural Urban

46.7 53.3

41.6 58.4

46.4 53.6

45.2 54.8

n.s.

Income level <1500 €/month 1500–2500 €/month >2500 €/month

49.0 31.0 20.0

29.8 44.2 26.0

40.9 35.7 23.4

40.0 36.7 23.3

*

Family size 1–2 3–4 5 or more

32.7 51.4 15.9

25.0 49.1 25.9

26.2 47.5 26.2

27.6 49.1 23.3

n.s.

Place of purchase for ham Hypermarket Supermarket Butcher’s shop Other

33.6 17.8 35.5 13.1

29.2 19.5 38.1 13.3

23.0 14.2 45.4 17.5

27.5 16.6 40.7 15.1

n.s.

Purchasing format (IMFH) Sliced and packed Over the counter Whole ham

10.1 29.0 60.9

12.3 30.9 56.8

17.2 30.6 52.2

14.1 30.3 55.6

n.s.

Purchasing format (IH) Sliced and packed Over the counter Whole ham

12.3 16.4 71.2

19.8 29.1 51.2

10.9 37.2 51.8

13.9 29.7 56.4

**

Purchasing format (SH) Sliced and packed Over the counter Whole ham

47.5 21.3 31.3

48.9 29.3 21.7

42.2 34.0 23.8

45.5 29.5 25.1

n.s.

Frequency of consumption (IMFH) Once a week or more Once or twice a month Never

23.5 66.7 9.8

27.1 62.6 10.3

32.8 58.0 9.2

28.7 61.6 9.7

n.s.

Frequency of consumption (IH) Once a week or more Once or twice a month Never

34.3 51.5 14.1

51.0 43.3 5.8

44.8 41.4 13.8

43.8 44.6 11.7

*

Frequency of consumption (SH) Once a week or more Once or twice a month Never

62.2 20.4 17.3

55.0 32.1 12.8

52.0 32.4 15.6

55.4 29.3 15.3

n.s.

Appreciate DO Yes No

72.0 28.0

85.5 14.5

81.0 19.0

79.8 20.2

*

Willingness to pay an extra price for DO 0% <10% 10–20% >20%

43.0 28.0 20.6 8.4

27.7 36.6 29.5 6.3

32.8 32.8 30.1 4.4

34.1 32.6 27.4 6.0

*

IMFH, Iberian mast-fed ham; IH, Iberian ham; SH, Serrano ham; DO, Designation of Origin. a Differences significant at: *p < 0.05, **p < 0.01, ***p < 0.001; n.s.: non-significant.

The products used in the simulations are listed in Table 6. In order to allow the comparison between the different products, the attribute ‘‘Purchasing format” has been set as ‘‘Whole Piece”.

These four products try to represent broadly what can be found in the supermarkets or butcher’s shops of the area, with quality and high price products, as against other products from intensive rearing selling at lower prices.

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F.J. Mesías et al. / Meat Science 83 (2009) 684–690 Table 6 Hypothetical ham products used in the simulations. Product 1

Product 3

Iberian mast-fed With DO 36 €/kg Whole piece

Iberian With DO 26 €/kg Whole piece

Product 2

Product 4

Iberian Without DO 19 €/kg Whole piece

Serrano Without DO 8.6 €/kg Whole piece

DO, Designation of Origin.

Table 7 Estimated market shares a (%) for four hypothetical ham products. Results of the initial simulation, considering the overall sample and the three clusters.

Product Product Product Product

1 2 3 4

Overall sample

Cluster 1

Cluster 2

Cluster 3

43.23 14.16 17.36 25.25

50.47 10.28 4.67 34.58

32.10 29.20 38.94 14.60

47.27 14.75 11.75 26.23

Product 1: Iberian mast-fed ham with Designation of Origin (DO), 36 €/kg. Product 2: Iberian ham (IH) without DO, 19 €/kg. Product 3: IH with DO, 26 €/kg. Product 4: Serrano ham without DO, 8.6 €/kg. a Market shares calculated using the maximum utility model. This model considers that a consumer will select the product that provides him with the highest utility.

The simulations were carried out both for the overall sample and for each of the three clusters defined above. The estimated market shares obtained in the first simulation are given in Table 7. Results in Table 7 are in line with the preference functions described in Table 3 (overall sample) and Table 4 (clusters). For example, in Clusters 1 and 3, Product 2 is preferred to product 3 mainly because of its lower price, which is more important for these consumers than DO. Another example is the fact that, in Cluster 2, Product 1 is the second most preferred, although it is an Iberian mast-fed ham. This can be explained because Product 1 is the most expensive, and higher levels of price add higher levels of utility for the consumers belonging to Cluster 2. In order to determine the amount a consumer is willing to pay for Iberian mast-fed ham as against Iberian ham, new simulations were carried out by reducing the price of Product 3 (Iberian ham with DO) to a level for which the market share of Product 3 exceeded that of Product 1 (Iberian mast-fed ham with DO). After several repetitions, the final price for each cluster was determined. The results are shown in Table 8.

As shown in Table 8, the overall sample is willing to pay an additional 20.2 €/kg to get Iberian mast-fed ham instead of Iberian ham. Nevertheless, Cluster 1 is ready to pay just 15.9 € more per kilogram for the Iberian mast-fed ham, as compared with 20.8 in the case of Cluster 3. These results are in line with the characteristics of each cluster: thus, out of the three, Cluster 3 gave the least importance to the product’s price, and hence obviously valued less the lower price of Iberian ham. As Cluster 3 is also the one that gives the most importance to the Type of ham (the most preferred being Iberian mast-fed), the conjunction of these two attributes led to the highest extra price. The results for Cluster 1 involve the same attributes, but with different signs: less importance for Type of ham, and greater for Price. It should be kept in mind that the results for Cluster 2 cannot be compared with those of Clusters 1 and 3. The linear like relationship between price and utility implies that, if the price of Product 3 is reduced, the preference for this product will decrease, as indeed occurred. This, together with the greater preference for Iberian ham vs. Iberian mast- fed ham, explains why the result for Cluster 2 does not really show the increase in price that these consumers are willing to pay for Iberian mast-fed ham. The increase in the price that consumers are willing to accept has to be compared with the costs of the production process. The main difference between Iberian mast-fed ham and Iberian ham is the raw material, i.e., Iberian pigs fed mainly on mast or on fodder, respectively. Fig. 1 shows the price evolution for Iberian mastfed pigs and Iberian pig. These prices increase substantially once the pig is slaughtered and butchered, as the best pieces (e.g., the ham) fetch the highest prices: Iberian mast-fed ham costs 7–9 €/kg, and Iberian ham, around 3–3.1 €/kg (www.lonjaextremadura.org). Finally, mast-fed hams usually spend more time in the ‘‘bodega” (natural curing warehouse) as part of their maturing process, which means greater financial costs, giving final production costs of 20–21 €/kg for Iberian mast-fed hams vs. 9–10 €/kg for Iberian ham. Obviously, these are not consumer prices, as the companies and distributors have to include their markups and taxes. The final difference in price between the two types of ham can therefore reach 15–20 €/kg, depending on the length of the supply chain to market. The price differentials observed suggest that Cluster 3 is the only one always be willing to buy an Iberian mast-fed ham, as consumers belonging to Cluster 1 sometimes may find it too expensive. These results must be carefully considered by the producers of Iberian mast-fed ham. Cluster 3 is their market niche and it is also their most interesting consumer segment, as it has the largest percentage of frequent Iberian mast-fed ham consumers, and its members are in the medium–high income levels. If the producers wanted to widen their market, Cluster 1 could be the natural option, due to its preference structure (its most preferred type is Ibe-

Table 8 Estimated market sharesa (%) considering reduced prices for Product 3 and economic value of mast-fed attribute.

Product 1 Product 2 Product 3 Product 4 Economic value of mast-fed attributeb

Overall sample Price Product 3 = 15.8 €/kg

Cluster 1 Price Product 3 = 20.1 €/kg

Cluster 2 Price Product 3 = 24.4 €/kg

Cluster 3 Price Product 3 = 15.2 €/kg

35.10 11.70 35.59 17.61 20.2 €/kg

37.38 0.00 37.38 25.23 15.9 €/kg

31.86 21.68 31.86 14.60 11.6 €/kg

35.79 8.20 36.89 19.13 20.8 €/kg

Product 1: Iberian mast-fed ham with Designation of Origin (DO), 36 €/kg. Product 2: Iberian ham (IH) without DO, 19 €/kg. Product 3: IH with DO, 26 €/kg. Product 4: Serrano ham without DO, 8.6 €/kg. a Market shares calculated using the maximum utility model. This model considers that a consumer will select the product that provides him with the highest utility. b The economic value of the mast-fed attribute is calculated as the difference between the prices of Products 1 and 3.

690

F.J. Mesías et al. / Meat Science 83 (2009) 684–690

3 2.5 2 1.5 1 0.5 0 31/12/2006

29/06/2007

26/12/2007 Iberian Mast-Fed Pigs

23/06/2008

20/12/2008

18/06/2009

Iberian (fodder) Pigs

Source: Own data and 3tres3iberico.com Fig. 1. Price evolution (2007–2009) for Iberian mast-fed pigs and Iberian pigs (€/kg live weight).

rian mast-fed). Nevertheless, Cluster 1 shows the lowest frequency of consumption of Iberian mast-fed and Iberian ham, and the highest for Serrano ham, probably reflecting its lower income level. Finally, Cluster 2 is an interesting segment, as their direct linear relationship between price and utility implies a wide potential for high quality, and expensive, products. Although Cluster 2 is the one of the three clusters with the highest income level, the most preferred type of ham is Iberian ham, non mast-fed. This indicates a need for information in order to increase its appreciation of the characteristics of Iberian mast-fed ham. 4. Conclusions Conjoint Analysis has been used to determine the most important attributes in shaping the preferences of the consumers for Iberian dry-cured ham. These attributes were the Type of ham (43.5%) and the Price (38.5%) and the attribute that least affected the choice of the different types of ham was the Purchasing Format (5.6%). The results of the Conjoint Analysis, in the form of a preference function, are suitable for used in segmenting the consumers, as evident in the three clusters that were found. It is remarkable that Cluster 2 shows an unusual behavior in the food market, as it is the use of price as a signal of the product’s quality, with utility growing as the price increases. Thus, segmentation according to preferences can be a useful tool to develop different marketing strategies for each segment of the market. Another interesting application of Conjoint Analysis was the possibility of determining the economic value that consumers put on the presence or absence of a certain level of an attribute. This technique was used to determine the economic value that consumers put on the presence of the mast-fed attribute, which could be used by Iberian dry-cured ham firms to select market segments (only some consumers are always willing to pay for Iberian mast-fed ham) or to change marketing policies (other segments could be interesting targets, but after prior education). References Andrés, A. I., Cava, R., Mayoral, A. I., Tejeda, J. F., Morcuende, D., & Ruiz, J. (2001). Oxidative stability and fatty acid composition of pig muscles as affected by rearing system, crossbreeding and metabolic type of muscle fibre. Meat Science, 59(1), 39–47. Andrés, A. I., Cava, R., Ventanas, J., Thovar, V., & Ruiz, J. (2004). Sensory characteristics of Iberian ham, Influence of salt content and processing conditions. Meat Science, 68, 45–51. Cattin, P., & Wittink, D. R. (1982). Commercial use of Conjoint Analysis. Journal of Marketing, 46, 44–53. Cava, R., Ventanas, J., Ruiz, J., Andrés, A. I., & Antequera, T. (2000). Sensory characteristics of Iberian ham, influence of rearing system and muscle location. Food Science and Technology International, 6, 235–242.

Cunhal-sendim, A., Albiac, J., Delfa, R., & Lahoz, F. (1999). Quality perception of light lamb carcass. Archivos de Zootecnia, 48, 187–196. Cheng, H. W., Clarke, A. D., & Heymann, H. (1990). Influence of selected marketing factors on consumer response to restructured meat steaks, a conjoint analysis. Journal of Sensory Studies, 4, 165–178. Cruz, J. (2005). La producción y comercialización de jamón curado en España. Eurocarne, 135, 23–34. European Commission. (2006). Case studies. PDO Dehesa de Extremadura. Seville: European Communities. Gil, J. M., & Sánchez, M. (1997). Consumer preferences for wine attributes, a conjoint approach. British Food Journal, 99(1), 3–11. Gillespie, J., Taylor, G., Schupp, A., & Wirth, F. (1998). Opinions of professional buyers towards a new, alternative red meat, Ostrich. Agribusiness, 14(3), 247–256. Green, P. E., & Srinivasan, V. (1978). Conjoint analysis in consumer research, issues and outlook. Journal of Consumer Research, 5, 103–123. Grunert, K. (1997). What’s in a steak? A cross-cultural study on the quality perception of meat. Food Quality and Preference, 8(3), 157–174. Hair, J. F., Anderson, R. E., Tatham, R. L., & Black, W. C. (1999). Análisis multivariante. Madrid: Prentice Hall. Huang, C. L., & Fu, J. (1995). Conjoint analysis of consumer preferences and evaluations of a processed meat. Journal of International Food and Agribusiness Marketing, 7(1), 35–53. Kupiec, B., & Revell, B. (2001). Measuring consumer quality judgements. British Food Journal, 103, 7–22. MAPA (2007). La alimentación en España, 2006. Madrid: S.G.T. Ministerio de Agricultura, Pesca y Alimentación. Martínez-Carrasco, L., Brugarolas, M., Del Campo, F. J., & Martínez, A. (2006). Influence of purchase place and consumption frequency over quality wine preferences. Food Quality and Preference, 17, 315–327. Mesías, F. J., Martínez-Carrasco, F., & Albisu, L. M. (1997). Análisis de las preferencias de los detallistas de jamón curado mediante el análisis conjunto. ITEA, 93A(1), 41–55. Mesías, F. J., Escribano, M., Rodríguez de Ledesma, A., & Pulido, F. (2005). Consumers´ preferences for beef in the Spanish region of Extremadura, a study using Conjoint Analysis. Journal of the Science of Food and Agriculture, 85, 2487–2494. Murphy, M., Cowan, C., & Henchion, M. (2000). Irish consumer preferences for honey, a conjoint approach. British Food Journal, 102(8), 585–597. Ness, M., & Gerhardy, H. (1994). Consumers preferences for quality and freshness attributes of eggs. British Food Journal, 96, 26–34. Ruiz, S., & Munuera, J. L. (1993). Las preferencias del consumidor, estudio de su composición a través del análisis conjunto. Estudios Sobre Consumo, 28, 27–43. Ruiz, J., Ventanas, J., Cava, R., Timón, M. L., & García, C. (1998). Sensory characteristics of Iberian ham, influence of processing time and slice location. Food Research International, 31, 53–58. Sánchez, M., Goñi, C., Marañón, I., & Martín, S. (2000). Diferencias en las preferencias entre los consumidores de carne de vacuno etiquetada y no etiquetada. ITEA, 96A(1), 40–55. Sánchez, M., Sanjuán, A., & Akl, G. (2001). El distintivo de calidad como indicador de seguridad alimenticia en carne de vacuno y cordero. Economía Agraria y Recursos Naturales, 1(1), 77–94. Sayadi, S., Gonzalez, M. C., & Calatrava, J. (2005). Ranking versus scale rating in conjoint analysis, evaluating landscapes in mountainous regions in southeastern Spain. Ecological Economics, 55, 539–550. Souza, D., & Lucas, R. (2001). Conjoint measurement of preferences for traditional cheeses in Lisbon. British Food Journal, 103, 414–424. Steenkamp, J. B. (1987). Conjoint measurement in ham quality evaluation. Journal of Agricultural Economics, 38, 473–480. Varela, J., Braña, T., & Rial, A. (1997). Diseño del producto ideal mediante el análisis conjunto. ESIC MARKET, Octubre–Diciembre, pp. 67–74. Wittink, D. R., & Cattin, P. (1989). Commercial use of Conjoint Analysis, an update. Journal of Marketing, 53, 91–96.