INTRODUCTION

There are many distinct types of wine consumers located around the world and a variety of studies have attempted to understand what motivates them to purchase wine. Is it because of their age, gender, the price, expert rating, or what is on the label? And now, new considerations include the environmental or sustainability impact of the wine, specifically if that wine has a certification [1].

Many studies have studied the impact that age has on purchasing and consumption [2–4]. Millennials, also known as echo boomers, generation y, or nexters, were found to go to tasting rooms, but do not purchase as much as the older customers [5]. There is some discrepancy in the literature as to who consumes the most wine. One study shows younger people consume more wine [6], and another posits they consume less [7]. Other studies have concluded that younger people have a greater awareness for the environment and might be motivated to purchase sustainably produced wines, in their respective countries [8–14]. This study seeks to clarify this confusion and gap in the literature and to analyze it at a transnational level.

Research has found that millennials are motivated to buy wine when exposed to promotion and labelling [15,16]. They are ready to pay more for wines, use the internet to find an appropriate price, and tend to consume a higher share of white wines [7,17]. Millennials are moved by wine advertising that shows people relaxing and having fun. They insist on innovative labelling and packaging [18]. Further studies found that younger consumers aged 31 to 40 often lack self-confidence in buying a bottle of wine [19]. Conversely, another study, based on French consumers, found that older consumers were more likely to buy organic wines [20].

This research believes that younger consumers will be more likely to buy and pay more for sustainably produced wines. After all, younger generations are more concerned with energy conservation and carbon impacts of a winery [3] and millennial women, who live in urban areas are also concerned about the carbon effect of their wines [13]. Conversely, the youngest consumers, with above average incomes, buy more wine, at a lower price, and are not interested in promotions and certifications [21]. The literature has very mixed and inconsistent results on the age effect on attitudes towards sustainable wine and it seems to differ based on the country where the study was conducted.

In a study of U.S. millennials, [22] identified significant differences in how younger versus older consumers search for and select wines. Millennials differed by gathering information from talking to friends/family and store employees and purchased wine based on medals won, label imagery and alcohol content, rather than origin and price. Another U.S. based study by [23] surveyed 540 wine consumers and the results demonstrated the importance of eco-labels to positively influence purchase intention, quality perception and attitudes towards sustainably produced New Zealand wine. [24] questioned 2000 Italian wine consumers and results indicate that millennials regard sustainability in wine consumption as a more important issue than older consumers. With respect to gender, females have a greater tendency to consider the environmental, social and the economic components compared with males.

Meanwhile it seems that sustainability is not a factor in the purchasing of wine [25], or it just depends where the individuals live. Young Italians would pay more for sustainably certified wines [11]. California wine consumers also value sustainable production [8]. Positive and environmental awareness is an important factor for Italian consumers [11,26,27], those in Austria [28], and individuals in Spain [29]. Also in France [30], conducted an interesting analysis of 128,182 French wines and found that third party certified sustainable wines received higher expert ratings (average 6% higher) and by implication the potential for consumers to pay more for the eco-certified wine.

In an attempt to clarify the age effect of consumers with respect to sustainable wines and a willingness to pay for these wines, this paper analyzes the differences between younger (18 to 44 years) and older (45 years and older) consumers with respect to sustainably certified wines and their willingness to pay (WTP) a premium for it transnationally in seven countries (the United States, South Africa, Netherlands, Italy, France, Chile and Australia). Given that most of the existing literature is focused solely on one country or region, this study attempts to fill a void in the literature by using a transnational approach in hopes of ascertaining what is happening at a more global level. The methodology includes the use descriptive statistics and the two-sample t-test to analyze the significant factors which determine consumers attitudes towards sustainably produced wines. Also, Pearson’s chi-squared test and ordinal logistic regression with marginal effects is used to examine whether the willingness to pay a premium for sustainably produced wines differs significantly based on age.

In this context the following six hypotheses have been developed. It is believed that younger consumers, compared to older consumers, will be more likely to:

H1: buy sustainably produced food and wine.

H2: view sustainable certification as important.

H3: be willing to pay a premium for sustainably certified wine.

The rationale for these hypotheses is the belief that younger consumers have a greater interest in their impacts on the environment and greater knowledge about sustainability protocols compared to older consumers. While they may have less funds at this age, they will place a greater importance on buying a sustainably produced product so will spend more compared to those who are older and have more disposable income.

When comparing younger consumers to older consumers the factors that affect willingness to pay a premium for sustainably produced wines are hypothesized as:

H4: an increase in age has a negative influence.

H5: gender, education, income, wine knowledge has no influence.

H6: previously purchased sustainably produced products has a positive influence.

The rationale for these hypotheses is that older wine drinkers tend to take less risks with trying new things. It is also believed that sustainability is important equally to people of different gender, education and income—it is believed that age will be the primary indicator. It is hypothesized that younger age also tends to correlate with positive views on certification and that those individuals tend to buy other sustainably produced products.

MATERIALS AND METHODS

An online survey was developed to ascertain consumer knowledge, attitudes and willingness to pay for sustainably produced wine in seven countries (the United States, South Africa, Netherlands, Italy, France, Chile and Australia). The online survey was available for one year, during 2020 and 2021, was administered using Qualtrics and took 10 minutes to complete. Data was collected from approximately 2500 consumers (see Table 1 for the breakdown by country). Ethical considerations for this study were approved by the Collaborative Institutional Training Initiative (CITI Program) (approval number 24071150).

There were four parts to the survey. First, the questionnaire asked consumers about their wine consumption. Specifically, they were asked about how many bottles they purchased each month, how much they paid for a bottle, how often they visit a winery, why they drink wine, what their favorite varietal is, where they buy wine, and any other important considerations they think about when buying wine. Second, consumers were asked about their views about sustainably produced food and wine, and their purchasing behavior of same. Next, respondents were questioned whether they would purchase, and what their willingness to pay a premium for sustainably produced wine would be. They could choose from the following price values: $1–5; $6–10; $11–15; $16 or more. Finally, consumers were asked about their socio-demographic characteristics: income, age, education, and gender.

The sampling approach included surveying wine drinkers over the age of 18. All surveys were terminated if they were under the age or did not drink wine. In addition, convenience sampling was utilized to target the respondents. Specifically, they were found through wine club newsletters, email lists of individual and collective wineries and their associations, and personal contacts of the researchers through social media and networks. This approach is a limitation of the study, however the alternative methods of random sampling and recruitment from the general public or representative groups, either online or face-to-face, would have been either overly time consuming and/or would have required significant cost.

Descriptive statistics identified if age, gender or other sociodemographic details influenced consumers’ attitudes and willingness to pay more for sustainably produced wine.

Other methods include a two-sample t-test to analyze the significant factors which determine consumers attitudes towards sustainably produced wines. Pearson’s chi-squared test and ordinal logistic regression with marginal effects is used to examine whether the willingness to pay a premium for sustainably produced wines differs significantly based on age.

Pearson’s chi-squared test was deployed to test if the willingness to pay a premium for sustainable wine differed because of the demographic characteristics and past purchasing behavior of consumers. The test compares the observed and the expected frequencies of certain categories and it assumes the independence of the residual, and it can’t be used on a repeated-measure design.

WTP a premium for sustainable wine was constructed as an ordinal variable with respondents asked whether they want to pay $0, $1–5, $6–10, $11–15 greater than $16; for the wine. It is therefore logical to use ordinal logistic regression with marginal effects to examine whether the willingness to pay a premium for different certified wines differs significantly based on wine knowledge, attitudes, and socio-demographic characteristics.

Statistical Software for Data Science (STATA Version 18) was used for the analysis.

RESULTS

The characteristics of the sample can be found in Table 1. Of the 2455 individuals surveyed, the results included a perfect balance with respect to gender. 50% were male and the other 50% were female. With respect to age, 60% were under the age of forty-four. In addition, 66% of the respondents had attended college/university and the median income from all was USD 95,000.

The descriptive analysis of the results is found in Table 2. It was found that younger consumers viewed sustainable wine certification as very or extremely important (38% vs. 33%), compared to older consumers.

TABLE 1

Table 1. Respondent attributes.

TABLE 2

Table 2. Descriptive analysis.

Figures 1 and 2 further highlights these results. They show that younger individuals had a higher willingness to pay for sustainable wine than older respondents. Moreover, young respondents who view wine certification as moderately to extremely important, had a higher willingness to pay for sustainable wines than older respondents with identical views.

FIGURE 1

Figure 1. Willingness to pay for sustainably produced wine by age group and views on its importance.

FIGURE 2

Figure 2. Willingness to pay for sustainably produced wine by age group and by gender.

TABLE 3

Table 3. Two-sample t-test (mean difference between ages 18–44 and age 45 or more).

Additional analysis includes a two-sample t-test (see Table 3). This shows that there is no significant difference between old (age 45 or higher) and young (age 18–44) consumers regarding the buying of certified food having an impact on buying sustainably certified wines (mean diff: 0.01; p-value = 0.55). However, the following four results are significant at a 95% confidence interval. First, young consumers buy certified wine significantly more than older consumers (mean diff: 0.28; p-value < 0.05), even though, on average, older consumers purchase more wines compared to younger consumers (8.41 vs 5.13). Furthermore, younger consumers are marginally more likely to pay a premium for these certified wines (mean diff: 0.13; p-value < 0.05) as they view sustainable certification as marginally more important than the older consumers (mean diff: 0.14; p-value < 0.05).

TABLE 4

Table 4. The association of age and willing to pay premium for sustainably certified wines.

Table 4 analyzes the association between age and willingness to pay a premium for sustainable certified wines. This analysis indicates that consumers aged 18–44, have a higher willingness to pay for sustainable wines compared to older aged consumers (age 45 and over) in 6 out of the 7 regression models (1 bivariate and 6 multivariate). The initial estimated results found that consumers aged 18–44 had an approximate 1.20 times higher likelihood of paying a premium for sustainable wines than older consumers. These results are confirmed by additional analyses. The ordinal logit model examined all of the respondents together and also separated the two groups to determine the willingness to pay a premium for sustainably produced wine.

TABLE 5

Table 5. Factors affecting WTP premium for sustainably produced wines—all countries and all age groups.

Table 5 demonstrates the key factors that influences the consumer willingness to pay a premium for sustainable wines from all countries. First, it is found that gender (female = 1 and male = 2) significantly influences the willingness to pay a premium for sustainably certified wines. Holding other things constant, female consumers showed a higher likelihood (1.17 times more) to pay a premium for sustainably certified wine. Second, the results indicate that consumers who view sustainable wine certification as important have a 2.61 times higher likelihood of paying more for sustainable wines compared to those who don’t find certification to be as important. Holding all other variables constant the probability of no additional payment decreases by 14% and paying an additional $1–5 increases by 9% for consumers who think sustainable wine certification is important. For the variable in age, the odds ratio is 0.97. This suggests that for every addition year in age there is a reduction in the likelihood to pay more for sustainable wines. However, this item is not statistically significant. The age effect is further corroborated by the results of the marginal effect analysis. This shows that the probability of not paying more increases by 0.3% with every additional year of age (holding all other variables constant at their mean). Furthermore, it is important to note that higher income or higher wine knowledge did not have a statistically significant probability of paying a premium for sustainable wines compared to those with lower self-reported income or wine knowledge.

TABLE 6

Table 6. Factors affecting WTP a premium for sustainably produced wines (ages 18–44).

TABLE 7

Table 7. Factors affecting WTP a premium for sustainably produced wines (aged 45 or more).

The ordinal logit regression model results for consumers aged 18–44 and 45 or more can be found in Tables 6 and 7, respectively. Similarly, to all age group results in Table 5, ‘views sustainable certification as important’ was found to be a significant factor in determining the willingness to pay a premium for sustainably produced wines. Consumers who view wines with sustainable certification as important had a 2.48 (age 45 or more) and 2.72 (aged 18–44) times higher probability of paying more for sustainably produced wines than those who do not have the same view. In addition, for the 45 or more-age group, higher education is associated with a significantly lower likelihood to pay a premium for sustainably produced wine (OR: 0.89, 95% CI: 0.83–0.96).

DISCUSSION

This research sought to identify whether consumers from seven wine consuming countries (the United States, South Africa, Netherlands, Italy, France, Chile and Australia) were willing to pay more for sustainably produced wines and if age, primarily, (and other factors) was a significant influence on individual consumers’ decisions. The research attempted a cross-country approach with almost 2500 wine consumers surveyed in these seven countries to see if age has a significant role in the decisions of consumers to purchase sustainably produced wines.

Mixed results exist for the first hypothesis. Surprisingly, the relationship of buying food with eco certification did not hold for younger consumers when compared to older consumers, as this relationship was not statistically significant. Yet, the age difference was initially significant when only buying wine was considered, with younger consumers more likely than older consumers. This inconsistency is surprising but consistent with other studies looking at willingness to pay for environmental/ecological/sustainable wines in individual countries [13,29,32].

The findings confirm that the second hypothesis is correct. Younger consumers, compared to older consumers, view sustainable certification as marginally more important. The third hypothesis that the willingness to pay for sustainably produced wine is higher for the younger age group was true, however only marginally more and was not statistically significant compared to older consumers. Rather it seems that there is a greater relationship between attitude about sustainability and behavior with respect to willingness to pay, which may also be linked to age. Nevertheless, authors [33] discussed the variance between positive attitudes towards sustainability and how they frequently fail to translate into actual purchase behavior.

There were also interesting results when the factors that influence the attitudes of both younger and older consumers were analyzed. The fourth hypothesis holds true, that an increase in consumer age negatively influences willingness to pay more for sustainably produced wines.

The fifth hypothesis has mixed results. It was surmised that gender, education, income, wine knowledge had no influence. However, gender was positive and statistically significant in the combined analysis as women were more likely to pay more. Furthermore, educational levels have a negative impact on the willingness to pay for sustainably produced wines. One explanation for these results could be the negative quality perception of sustainably produced wines that are more prevalent in the older age group. With respect to income, there were surprising results. An increase in income does not seem to effect either age group on their willingness to pay more for sustainably produced wine. Finally, for this hypothesis, wine knowledge was also a surprising result with no influence of that factor on willingness to pay in either age group.

The sixth hypothesis holds. Younger consumers that have previously purchased sustainably produced products will have a higher willingness to pay for sustainably produced wine compared to older customers. And consumers from both age groups that value sustainably produced products have a higher willingness to pay for sustainably produced wine than those who do not.

CONCLUSIONS

Overall, the results are interesting, timely and relevant. The research finds that younger consumers do have a marginally higher willingness to pay for sustainable wine than older consumers and that gender is also a factor. Women are more interested in paying a premium for sustainability certified wines. Interestingly, income and wine knowledge are not factors or significant in the findings. Having more money or years of wine experience is not necessarily likely to encourage paying a premium for sustainable wine. The most important finding is that those who view sustainability certifications as important have a 2.6 times likelihood to pay more for sustainable wines. This is especially true for young consumers who view wine certification as moderate to extremely important. While older consumers buy more wine, in general, than younger consumers, the younger customers buy more certified wines. And those younger people that are moderately or extremely interested in wine certifications are willing to pay more.

This research therefore has a variety of implications for the industry and marketing of sustainably produced wines. Wealth and general wine knowledge do not seem to matter. In fact, gender, age, and especially knowledge about wine sustainability certifications are most important. While these are not necessarily translating into greater sales and profits given consumer behaviors, there is hope that it can if marketers can target their efforts. It is possible that more education about wine sustainability certifications will lead to greater purchases and a higher willingness to pay for them—especially if the education is targeted to those that are younger and female. The future of wine is always changing, but producers and marketers will need to make greater efforts to educate the public about their sustainability certification process if they want to increase this specific market and generate greater profits.

While the research has generated interesting results, there are some potential limitations to the study with respect to the sampling methods and geographic selection. The sample of convenience could potentially bias the results to a more educated, higher income, more experienced group of wine consumers. It is uncertain if the average consumer was captured in the survey population. Also, there are concerns that convenience sampling being used in wine consumer research is inferior to face to face or telephone sampling particularly due to the potential lack of representativeness to the entire population of each of the countries surveyed [34].

Furthermore, the countries selected were also one of convenience based on the residency of the research team. This resulted in a combined transnational analysis, and the results should not then be interpreted to represent any one of the countries analyzed. In addition, the analysis omits some of the more important wine producing/purchasing nations in the old and new world and omits some countries that have sustainability certifications. While there is a sustainability certification in Chile, Australia, France, South Africa, Italy and sub-regions of the United States (which are included in the study), both New Zealand (which had the first sustainability certification in the world), and Austria (which has one of the newest and most robust certifications) are omitted from the study.

Directions for future research could include a few different areas. First, it would be interesting to include all of the countries that currently have sustainability certifications and to determine if longevity of the program or level of adoption (percentage of wineries certified) would impact the results. Next, it would be thought provoking if consumers, in the same countries, were resurveyed every five to ten years to determine if a changes in the industry are translating to consumers behavior and/or if societal trends in sustainability are impacting purchasing behaviors. Finally, while consumers behavior is very interesting for sustainably certified wine, there is very little research on the motivations for certification adoption from the winery perspective. It is possible that consumers are not going to lead the needed changes to increase sustainability and that this paradigm shift must come from the producers themselves.

DATA AVAILABILITY

The dataset of the study is available from the authors upon reasonable request.

AUTHORS’ CONTRIBUTIONS

DM, JG, LV, AAU, and RM designed the study and conducted the data collection. RR, JG, and DM analyzed the data. DM and JG wrote the paper with input from all authors.

CONFLICTS OF INTEREST

The authors declare that they have no conflicts of interest.