Expression of Behavior and Attitudes toward Sustainable Tourism in the Youth Population: A Search for Statistical Types

: Youth attitudes and behavior in tourism activities are crucial for sustainable tourism development. This study aims to identify the statistical types of youth according to their expressed behavior in sustainability and attitudes toward sustainable tourism development. Survey data were collected from 1085 respondents representing different Baltic Sea countries—Latvia, Lithuania, and Russia. A unique research instrument, constructed by the authors, was developed for the empirical research, responding to the latest theoretical insights and models and was empirically validated by statistical methods (the factor validity of the scales was tested with Cronbach’s alpha coefﬁcient, etc.). Attitudes towards sustainable tourism development were measured with the SUS-TAS scale. The factor clustering method used in the study identiﬁed the statistical types of the youth included, according to the expression of sustainable behavior and the attitudes toward sustainable tourism development. The results indicated that the majority of youth belong to the “oriented toward sustainable behavior” type (50.6%), while the analysis of youth attitudes showed that 71.5% belong to the socioeconomic type, indicating that young people prioritize the long-term socioeconomic wellbeing of the region, which can be achieved through efﬁcient management, tourism planning, and active public participation in the implementation of tourism policies.


Introduction
Until the COVID-19 pandemic, tourism significantly contributed to various global regions' wellbeing and socioeconomic growth and was in line with the main global trades [1].According to the World Tourism Barometer [2], before the pandemic, the tourism industry contributed 10.4 % to the global GDP and 1/10 jobs were supported by the tourism sector worldwide.It was considered as one of the fastest-growing industries, where at least one job vacancy out of every four new jobs globally belonged to the tourism sector.Tourism creates employment opportunities [3] and contributes to the growth of local and regional economies [4,5].
Majority of the contribution to the growth of tourism is represented by mass tourism.However, mass tourism has been commonly identified and criticized for being not a sustainable form of tourism [6].The COVID-19 pandemic has forced the tourism sector to shift toward domestic tourism in the short term, with the direction of safety and sustainability in the long-term perspective, as the need to balance its economic, social, and environmental impacts is self-evident [7].While the priority given in the past was mostly directed towards the economic benefits of tourism, nowadays, the greater concern is given to sustainability in Sustainability 2022, 14, 473 2 of 18 tourism [8].Sustainable tourism became one of the main goals in many countries' agendas as a main tourism policy component [9].
With the global outbreak of COVID-19 and its negative consequences for all sectors of the economy, the concept of sustainable development is gaining importance in the Baltic Sea region.In order to overcome the challenges of public security, integrity, and openness, the Council of the Baltic Sea States gives priority to sustainable development (especially in the field of green business development), with green and maritime tourism being seen as an important sector for regional economic recovery.This indicates a recognition of the need to increase regional visibility and employment opportunities for young people; encouraging more active participation in the processes of tourism reconstruction and development and increasing the confidence and involvement of young people in the activities of sustainable tourism development [10].As it is known from the sociocultural perspective, young people are considered an innovative force, and their choices can develop new attitudes of the general public towards tourism [11][12][13][14], as well as towards sustainable tourism.
Young people constitute the largest part of all travelers.In 2015, almost 1 in 4 tourists (about 25%) were aged 16-29; the total value of international youth tourism in 2020 reached about 400 billion USD, i.e., twice as much as in 2009 [15,16].Young people tend to save on travel and accommodation costs, while spending more money on attractions.Studies show that a given young tourist spends about a third more time in one place than the average tourist; young people tend to develop harmonious relationships with locals, giving priority to economic-type accommodation, which allows them to stay longer and have greater social opportunities [17][18][19].Thus, the purchasing power of young travelers provides significant economic opportunities for places of interest.
Based on sociocultural and future perspectives, it is noted that the current choices of young people will shape a new general public approach to tourism [12,20], and it is predicted that today's youth will also travel actively in the future [21].In other words, "the importance of the youth as a market segment is related not only to the fact that it is getting bigger, but also to the fact that it shows the market of the future" [22].In order for the tourism sector to prepare for the future by developing new products and services, it is necessary to assess the experiences and behavior patterns of young people traveling presently; emphasizing the importance of exploring the tourism behavior and values of this target group.
Traveling young people seek to discover new cultures, are more interested in, and interact with, local cultures, are more responsible in their outings, and have a greater awareness of the principles of sustainability [16,23].Thus, young people are becoming a demographic that helps in developing "responsible tourism".Therefore, the research on the behavioral patterns, motivations, attitudes, and sensitivities of young tourists towards sustainable tourism is becoming increasingly relevant today and is gaining new scientific and practical importance.
On the other hand, the study of young people's attitudes towards sustainable tourism can be based on a slightly different concept, i.e., assessing the attitudes of young people, not only as tourists but also as locals, towards the development of sustainable tourism in their region.It should be noted that, in recent decades, the research on local people's attitudes towards tourism has grown significantly [24][25][26].Local communities are recognized as having an important role to play in attracting tourists and increasing the attractiveness of the area.The behavior of the population and openness to the development of tourism and tourists determine the satisfaction of tourists and their desire to return, etc. [27].Accordingly, the attitude of local young people towards sustainable tourism is becoming a determinant of successful sustainable tourism [28].
Although there has been a significant increase in research on sustainable tourism and the youth population's attitudes towards sustainable tourism development in recent decades, there is still a lack of research identifying typologies of youth according to their attitudes towards sustainable tourism and the expression of sustainable behavior.The identification and qualitative specification of such statistical types, and the determination of the percentage of these groups in the population, is important information for enabling a focus on the very specific and real youth types when developing youth attitudes towards sustainable tourism development and strengthening sustainable behavior.Besides, because tourism policy makers and implementers should understand the existing demographics, in terms of sustainable youth tourism behavior and attitudes, this study identifies those types and provides significant insights (scientifically and practically useful).Moreover, in simply having such knowledge, it becomes possible to pay more attention to the formation of sustainable behavior of travelling youth, while creating and developing programs of tourism education and strategies for tourism development, etc.
The aim of the present article is to disclose the statistical types of youth according to their expressed behavior in sustainability and attitudes toward sustainable tourism development.The research contributes to the solution of the following questions: What behavior is expressed in relation to sustainability among the youth population?What are the attitudes toward sustainable tourism among youth?

The Concept of Sustainable Tourism Development
Since the appearance of the definition of sustainable tourism in the Bruntland Report [29], it has received international recognition among governments, businesses, and consumers [30].In the Bruntland Report, sustainable development is defined as "development which meets the needs of the present without compromising the ability of future generations to meet their own needs".However, initially, sustainability in tourism was mostly understood as the need to ensure environmental preservation and conservation; meanwhile, gradually, it has evolved into a more holistic approach, where sustainable development is understood as the balance of economic, social, and environmental dimensions.According to Fallon and Kriwoken (2003) [31], each of these dimensions takes into account the needs of visitors, industry, community, and environment.
The variety of sustainability definitions indicates the complexity of the concept, the wide range of its elements, and the broad application of its principles [32].The concept of sustainable development receives a constant critique from academia and businesses.It has been argued that the definition of sustainability is vague, as the development of sustainability, which refers to remaining the same, is hardly compatible and achievable in practice [33].The unregulated development of tourism can cause negative impacts in the social, economic, and environmental spheres due to pollution, degradation of landscapes [34], profit leakage out of the destination [35], increase in prices [36], poor working conditions [37], overcrowding, social tensions between host community and tourists, crime, or commodification of culture and traditions [38].
However, international bodies, such as the United Nations, advocate for tourism, arguing that it could be used as a tool for sustainable development.UNWTO and UNEP (2005) [39] introduced twelve aims of sustainable tourism, suggesting that tourism can contribute to economic viability, local prosperity, employment quality, social equity, visitor fulfilment, local control, community wellbeing, cultural richness, physical integrity, biological diversity, resource efficiency, and environmental purity.The intention to minimize negative impacts and to maximize tourism's positive contribution to the environmental preservation, economies, and wellbeing of local communities and visitors is also seen in numerous reports and guidelines for governments and businesses; with legislations, policy statements, and a wide range of business practices and marketing shifts responding to the challenges and demand for sustainable development.Tanguay et al. (2013) [40] argue that, as a response to different economic and sociocultural problems, the principles of sustainable tourism are becoming increasingly incorporated into the strategic planning documents of various destinations.
The growing body of tourism research and vigorous debates about the realization of sustainability's concept in practice [33,41] show that sustainable tourism development is one of the most significant topics in the tourism field.Due to its complexity, sustainable tourism development is closely linked to the concepts of carrying capacity [42], innovation [43], or competitiveness [44].Aall (2014) [45] and Swarbrooke (1999) [46] discuss that concepts, or terms, such as green tourism, environmentally friendly tourism, ecotourism, geo-tourism, alternative tourism, nature-based tourism, slow tourism, rural tourism, responsible tourism, soft tourism, and minimal impact tourism, are used interchangeably with sustainable tourism.The majority of these related terms focus on the environmental aspects of sustainability, even if they are not synonymous.UNWTO and UNEP (2005) [39] stated that sustainable tourism refers to principles of operation rather than being a distinct form of tourism.However, it is widely agreed that some forms of tourism, such as ecotourism, rural tourism, and natured-based or community-based tourism are more sustainable than mass tourism [47,48].
The recognition of the importance of sustainability for tourism development has called for the need to establish indicators which would be able to measure the impact of tourism [49,50].In order to estimate the impact of tourism and to identify existing issues of sustainability, various systems and frameworks of indicators have been developed [51,52].It is commonly cited that the concept of sustainable tourism loses its relevance without the indicators which can serve as a tool to monitor its impact [49,53,54].

Youth Attitudes toward Sustainable Tourism
An increasing number of scientific studies analyzing the attitudes and behavior of the young generation towards sustainable tourism consumption indicate the importance of the subject.It is seen as an appealing market with high potential, which influences the future development of tourism [22].However, it is also recognized that more information on youth travel habits and motivations is needed [55].
Youth is commonly defined as the generation aged between 15 and 29 years [23], or as teenagers, undergraduate students, youngsters, or young professionals [56].It is increasingly recognized as one of the fast-growing sectors in the international tourism field [57], with a significant contribution to local economies [58].According to Richards (2011) [49], the average length of a given trip is longer among young travelers, and they are more loyal to the destination.Moreover, it is agreed that the youth set trends in the international tourism market, and that youth are among the first who explore new tourism services and products, including the ones related to sustainable tourism [13].
A considerable number of studies [59][60][61][62] have analyzed youth's environmental attitudes and have indicated that the young generation is interested in ecology and nature's preservation.Han et al. (2018) [58] studied youth tourists' waste reduction behaviors and found that their awareness level about the issues related to environmental deterioration and the perceived green image of the destination encouraged them to consider the negative impact of pollution.
Badulescu et al. (2017) [63] found that masters students were interested in buying local products and in the protection of natural resources.This finding is in line with the findings of Beaumont (2011) [64], Berezan et al. (2014) [65], and Cini et al. (2012) [66], who found that ideas of ecotourism related to sustainable tourism practices are highly accepted by new generations of tourists.However, another study by Cini and Passafaro (2019) [67] revealed a lack of awareness and knowledge among the young population about the benefits of ecotourism to local communities and the environment.
The youth population's attitudes, behaviors, and motivations have also been examined in the context of backpacker tourism.Nok et al. [68], who studied the motivations and preferences of backpackers in Hong Kong, found that they avoid spending money on international brands and are interested in experiencing local cultures and food in traditional surroundings as a means of contributing to the development of sustainable tourism.Other studies [69][70][71][72] also recognize the role of backpackers, who are mainly represented by the youth [73], in their contribution to and impact on the development of sustainable tourism; moreover, backpackers prioritize food of local origin and locally operated services and they care about environmental protection, local cultures, and traditions, and they engage with host communities.
Buffa (2015) [74] analyzed the attitudes of young tourists towards sustainability, and the results revealed the interest of the youth in sustainability, indicating that it drives their decision-making path and motivations.The authors identified "hard path young tourists" and "soft path young tourists", where the members of the former group are mostly organizing the holidays themselves, are more aware of tourism's impact on the environment and local communities, and are willing to pay more for sustainable products or services.Cavagnaro and Staffieri (2015) [13] found significant differences among genders, where young women have stronger sustainability values compared with men and seek self-development through engagement with local communities; this means that travel businesses should be ready to respond to that need, and offer respective tourism offerings in the future.

Research Methodology
The present research was based on a quantitative research strategy.Five countries of the Baltic Sea region were selected for the study-Lithuania, Latvia, Estonia, Russia, and Poland.The duration of the online survey was October, 2020-March, 2021.
For the quantitative study, a survey method was used to reveal young people's expressed behavior of sustainable tourism and their attitudes towards sustainable tourism development.The survey method is one of the most commonly used and popular data collection methods for collecting factual data (expression of sustainable tourism) and subjective data (perceptions of sustainable tourism, values of sustainable behavior, attitudes, concepts, etc.).The survey, as a method of collecting data, can be carried out in many forms.One of them is an online survey, which allows an increase in the accessibility of the study population and the convenience of conducting the study, especially when organizing international studies.In the case of the survey, the online Mentimeter.com program-with which we officially purchased a license for a year-was used, which allowed us not only to conduct the survey, but also to visually present the results of the current survey to a respondent.It should be noted that respondents representing Russia, due to the existing foreign language barrier, were interviewed using Google survey means.In this case, the research instrument was translated into Russian and provided to respondents in their national language.The validity of the research instrument was ensured by expert validation of the research instrument.

Research Sample
In an empirical study, it is necessary to identify the field of study and the sample.The field of this research is young people from Baltic Sea countries, studying or working in the tourism sector, or who are interested in tourism development issues.The sample of the survey was 1085 respondents, representing different countries, as follows: Latvia (43.5%),Lithuania (28.7 %), Russia (8.7%), Estonia (2.3%), Poland (2.8%), and other countries (4.0%).
Since the survey sample can be formed using both statistical and non-statistical methods, in the case of the survey, in order to represent the sample, a statistical, targeted, and multi-level sample was chosen; this was designed so that each 16-30-year-old person, depending on the purpose of the survey, with links to the field of tourism (studying, working), should have an equal chance of being interviewed.Methodological insights suggest that the reliability of survey data depends, largely, not on the exact size of the calculated survey sample, but on the way in which respondents are selected.In this case, the respondents were selected with the help of tourism sector organizations, non-governmental organizations, and higher education institutions with links to the academic and professional field of tourism.
In the study sample, women dominated (78.6%).This is partly in line with the gender trends in those working and studying in the global tourism sector.The age of the respondents ranged from 16 to more than 30 years, the majority of the respondents were between 16 and 25 years old (47.2%).The majority of respondents included in the survey had a university degree (59.2%), 51.5% were students, 41.6% were employed, and 36.2% of the respondents were working or studying in a tourism-related field.

Research Instrument
A quantitative study must ensure that the instrument used for the study is valid and reliable.A unique research instrument, constructed by the authors, was developed for the empirical research, responding to the latest theoretical insights and models and were empirically validated by statistical methods (the factor validity of the scales was tested-Cronbach's alpha coefficient was used as the main measure of internal consistency of the research instrument scales; the factor validity of the scales is presented in the study results section, when presenting the data analysis).
The questionnaire consists of questions of a normative and descriptive nature.Normative questions reflect individual attitudes, while the descriptive questions focus on revealing the peculiarities of the expression in sustainable tourism.The questionnaire consists of four blocks of questions, while, in this article, we use three of them, as follows: (1) sociodemographic data; (2) expression of behavior in sustainable tourism; (3) attitudes towards sustainable tourism development (SUS-TAS scale).
The SUS-IAS scale of questions was applied to the analysis of attitudes of young people towards the sustainable development of tourism.An initial version of the scale was proposed by Choi and Sirakaya (2005) [27].It reflects the dimensions of the environmental impact of tourism, tourism planning, tourism management, and the impact of society on tourism.Later, this scale was used in various studies of sustainable tourism, improved, and adapted to different contexts.In the case of this study, a shortened and validated scale of 21 statements by Sirakaya-Turk and Gursoy (2013) [75] was used and was supplemented by 2 statements, corresponding to relevant issues.
The five-level Likert scale was used in the questionnaires to find out the expression and attitudes toward sustainable tourism.The structure of the Likert scales consisted of statements which were assessed by the respondents in terms of approval, indecision, and disagreement.

Methods of Research Data Analysis
The research data were processed using officially purchased SPSS (Statistical Package for Social Sciences) software and the Microsoft Excel program.In addition to the usual descriptive statistical methods, multidimensional statistical methods-factor and cluster analyses-were used.
The method of factor analysis was used to study the structure of the study variables.Factor analysis was used in the study to condense the primary study variables and form subscales.Factor analysis was performed on the basis of a correlation matrix.The main component method and VARIMAX rotation were used, i.e., rotation of variable axes in search of the maximum variance.One of the indicators that reveals the suitability of the matrix for factor analysis is the Kaiser-Meyer-Olkin (KMO) coefficient.The Kaiser-Meyer-Olkin coefficient measures adequacy for factor analysis and varies between 0 and 1, where values closer to 1 are better.A value of 0.6 is a suggested minimum.The coefficient of variation is a way to measure how spread out values are in a dataset, relative to the mean.Each factor is explained by the percentage of variance out of the total variance.The percentage of variance indicates the variance explained by each factor.The cumulative percentage shows the percentages of the total variance, explained by the factors (greater than 60%) [76].
In order to determine the psychometric appropriateness of the study variables, a reliability analysis of the scales was performed.The validity of the scales was assessed by Cronbach's alpha coefficient (acceptable coefficient variation range: 0.5≤ Cronbach's alpha <1) and the high internal consistency of the test instrument is indicated by high values of the Cronbach's alpha coefficient.There are different opinions in the scientific community regarding the lowest range of Cronbach's alpha.Some authors state that it should be higher than 0.6 or 0.7, some authors (for example, George and Mallery (2003) [77]) provide the following rules of thumb: ">0.9-Excellent, >0.8-Good, >0.7-Acceptable, >0.6-Questionable, >0.5-Poor, and <0.5-Unacceptable".This was followed in this study; all Cronbach's alpha coefficients ranged from 0.64 to 0.93.
In order to discover the expression of the features, we searched for the statistical types that exist in the target population, i.e., a statistical classification of respondents was performed.The cluster analysis was used for classification.Non-hierarchical clustering methods are often used to cluster large numbers of objects.Since the number of respondents in our study is quite large, a non-hierarchical clustering method, k-means, was chosen.Using the cluster analysis, groups of respondents with different expressions of the studied characteristics were distinguished.
The study follows the principles of research ethics, where anonymity is guaranteed, and the tone of address is respectful.The analysis of the research results was performed in accordance with the principle of validity: the presented research results are based on the opinion of the respondents.

Research Results
Trying to find out the expression of sustainable behavior of the youth, the scale of 19 questions-"How sustainable am I?"-has been presented, which aims to encourage a self-evaluation of the respondents with regard to sustainable behavior (evaluation scale: from 5-always to 1-never).
The graphic expression of the responses (Figure 1) shows that the expression of sustainable behavior of the respondents is mainly related to daily routine, i.e., when buying food products the seasonality and the availability of local products are taken into account, the purpose of using household appliances is to use them effectively (to switch them off when not in use), to save water, and to increasingly use the reusable bags in the shops, etc. Sustainable behavior is pursued at work as well as during studies.The research has showed that the weakest sustainable behavior of the youth is noticed while travelling, in their selected means of transport, or in buying second-hand items (clothes, equipment).It is important to emphasize that buying second-hand items is one of the sustainable behavior expressions which allows young people to add some items to their wardrobe without using additional resources in the manufacturing process.It is a very important expression of sustainable behavior as the fashion industry is responsible for 8-10% of global carbon emissions.
For the evaluation of the psychometric validity of the scale, and for construction of subscales, the factor analysis was used applying the method of principal components and VARIMAX rotation.The 19 statements of the scale were reduced to the 4 factors.Factor analysis presented a rather significant link of the majority of statements with the factors: their inside grouping is theoretically significant.The correlation coefficient of the statements with the factors was obtained (0.79 ≤ r ≤ 0.40), showing a high relationship between them.The factor descriptive variation ranges from 21.8% to 11.1% (the total explained variation is 58.2%).The Kaiser-Meyer-Olkin (KMO) coefficient, which is comparatively high in this scale (0.90), explains the extent to which the matrix is applicable for factor analysis.The inner consistency of single factors, expressed by the Cronbach alpha coefficient, ranges from 0.64 to 0.88 and shows that all 4 factors are quite homogeneous.Thus, the scale parameters presented, on the whole, meet the methodological norm of construct reliability and factor validity (Table 1).For the evaluation of the psychometric validity of the scale, and for construction of subscales, the factor analysis was used applying the method of principal components and VARIMAX rotation.The 19 statements of the scale were reduced to the 4 factors.Factor analysis presented a rather significant link of the majority of statements with the factors: their inside grouping is theoretically significant.The correlation coefficient of the statements with the factors was obtained (0.79 ≤ r ≤ 0.40), showing a high relationship between them.The factor descriptive variation ranges from 21.8% to 11.1% (the total explained variation is 58.2%).The Kaiser-Meyer-Olkin (KMO) coefficient, which is comparatively high in this scale (0.90), explains the extent to which the matrix is applicable for factor analysis.The inner consistency of single factors, expressed by the Cronbach alpha coefficient, ranges from 0.64 to 0.88 and shows that all 4 factors are quite homogeneous.Thus, the scale parameters presented, on the whole, meet the methodological norm of construct reliability and factor validity (Table 1).The first factor, constituting 21.8% of the spread of all the variables, called "Sustainable shopping", combined 8 statements that reflect the focus on environmentally friendly purchase of goods, i.e., natural fabric clothes, biocosmetics, equipment, sustainable behavior while shopping, etc.
The second factor, constituting 12.9% of the spread, called "Sustainable behavior with equipment", combined 4 statements reflecting sustainable behavior in using heating systems (switched to minimum if no longer needed), electric devices are switched off when not in use, and the tap is closed when water is not in use.
The third factor, constituting 12.5% of the spread, called "Thrifty usage of goods", combined 4 statements reflecting sustainable behavior while shopping, i.e., buying secondhand goods and repairing devices instead of buying new ones.
The fourth factor, constituting 11.1% of the spread, called "Sustainable traveling", combined 3 statements.

Statistical Types of Youth According to the Expression of Sustainable Behavior
In order to divide the respondents into groups by their expressed sustainability ("How sustainable am I?") the cluster analysis was made.As the number of the surveyed topics and subjects to be classified was considerably high, a k-means cluster analysis was chosen.The structure of the clusters was reflected by breaks.The surveyed were typologized by 5 scales of statistical evaluations: 5-"always", . . ., 1-"never".The most informative and easy-to-interpret representation of this data by dynamics is the respondents' division into 3 clusters-presented graphically in Figure 2.
A proportion of 18.4% of the subjects belonged to the first group (cluster), 50.6% belonged to the second cluster, and 31% of the subjects belonged to the third cluster.
In order to divide the respondents into groups by their expressed sustainability ("How sustainable am I?") the cluster analysis was made.As the number of the surveyed topics and subjects to be classified was considerably high, a k-means cluster analysis was chosen.The structure of the clusters was reflected by breaks.The surveyed were typologized by 5 scales of statistical evaluations: 5-"always", …, 1-"never".The most informative and easy-to-interpret representation of this data by dynamics is the respondents' division into 3 clusters-presented graphically in Figure 2. A proportion of 18.4% of the subjects belonged to the first group (cluster), 50.6% belonged to the second cluster, and 31% of the subjects belonged to the third cluster.
Cluster 1-expressed sustainability type.Almost 20% of the respondents belong to this type.This type of people is characterized by sustainability in all main spheres.They try to use water and electricity resources sustainably, to behave sustainably while shopping and traveling, using various equipment, etc.
Cluster 2-oriented toward sustainable behavior type.The biggest part of the youth-around 50%-belongs to this type.It has been noticed that people of this type are more neutral to sustainable traveling, they are not very thrifty when shopping, but they like buying goods that meet the principles of sustainability.However, this type of youth pay attention to sustainable behavior with equipment and saves electricity and water resources, etc.
Cluster 3-indifferent to sustainability type.A proportion of 13% of the young people belong to this type.All indexes of the statements evaluation scales are low.It can be assumed that this type of people are skeptical about sustainability.

Attitudes of the Youth toward Sustainable Tourism Development
Trying to find out the attitudes of the youth toward sustainable tourism, the SUS-TAS scale of attitudes of sustainable tourism development, composed on the basis of a validated variant by Sirakaya-Turk and Gursoy (2013) [75], has been presented.The 23question scale, Attitudes toward Sustainable Tourism, aims to identify respondents' attitudes toward social, economic, and ecological factors of sustainable tourism, tourism planning and management, and aspects of public and personal participation (evaluation scale: 5-strongly agree, …, 1-strongly disagree).The graphic expression of the responses (Figure 3) shows that, at present, respondents' attitudes toward the sustainable Cluster 1-expressed sustainability type.Almost 20% of the respondents belong to this type.This type of people is characterized by sustainability in all main spheres.They try to use water and electricity resources sustainably, to behave sustainably while shopping and traveling, using various equipment, etc.
Cluster 2-oriented toward sustainable behavior type.The biggest part of the youtharound 50%-belongs to this type.It has been noticed that people of this type are more neutral to sustainable traveling, they are not very thrifty when shopping, but they like buying goods that meet the principles of sustainability.However, this type of youth pay attention to sustainable behavior with equipment and saves electricity and water resources, etc.
Cluster 3-indifferent to sustainability type.A proportion of 13% of the young people belong to this type.All indexes of the statements evaluation scales are low.It can be assumed that this type of people are skeptical about sustainability.

Attitudes of the Youth toward Sustainable Tourism Development
Trying to find out the attitudes of the youth toward sustainable tourism, the SUS-TAS scale of attitudes of sustainable tourism development, composed on the basis of a validated variant by Sirakaya-Turk and Gursoy (2013) [75], has been presented.The 23-question scale, Attitudes toward Sustainable Tourism, aims to identify respondents' attitudes toward social, economic, and ecological factors of sustainable tourism, tourism planning and management, and aspects of public and personal participation (evaluation scale: 5-strongly agree, . . ., 1-strongly disagree).The graphic expression of the responses (Figure 3) shows that, at present, respondents' attitudes toward the sustainable development of tourism are mainly related to economic and managerial dimensions-i.e., responses related to a need for wellcoordinated sustainable tourism planning, the highest quality of tourism business services that would ensure visitors' needs, successful tourism management, and the assurance of economic benefits of sustainable tourism-achieved the highest rating.The research has shown that statements, such as "Our country is overcrowded because of tourism", "Tourists in our country disrupt my quality of life", "My quality of life has deteriorated because of tourism in our country", "Our country's natural environment is being protected now and for the future by the tourism industry", etc., obtained the lowest rating.
quality of tourism business services that would ensure visitors' needs, successful tourism management, and the assurance of economic benefits of sustainable tourism-achieved the highest rating.The research has shown that statements, such as "Our country is overcrowded because of tourism", "Tourists in our country disrupt my quality of life", "My quality of life has deteriorated because of tourism in our country", "Our country's natural environment is being protected now and for the future by the tourism industry", etc., obtained the lowest rating.For the evaluation of the psychometric validity of the scale and for construction of subscales, the factor analysis was used, applying the methods of principal components and VARIMAX rotation.From the 23 scale statements, 4 factors were extracted.Rather high correlations were obtained between the ratings of the statements and the extracted factors.The correlation coefficient of statements with the factors was obtained (0.52 ≤r ≤ 0.84) and a strong relationship was shown between them.The factor descriptive variation ranges from 28% to 9.5% (the total explained variation is 63.3%).The Kaiser-Meyer- For the evaluation of the psychometric validity of the scale and for construction of subscales, the factor analysis was used, applying the methods of principal components and VARIMAX rotation.From the 23 scale statements, 4 factors were extracted.Rather high correlations were obtained between the ratings of the statements and the extracted factors.The correlation coefficient of the statements with the factors was obtained (0.52 ≤ r ≤ 0.84) and a strong relationship was shown between them.The factor descriptive variation ranges from 28% to 9.5% (the total explained variation is 63.3%).The Kaiser-Meyer-Olkin (KMO) coefficient, which is comparatively high in this scale (0.91), indicated the extent to which the matrix is applicable for factor analysis.The inner consistency of single factors, expressed by the Cronbach alpha coefficient, ranges from 0.76 to 0.93, and shows that all 4 factors are quite homogeneous.Thus, the scale parameters presented, on the whole, meet the methodological norm of construct reliability and factor validity (Table 2).Attention should be paid to the meaningful grouping of statements within the factor.The first factor, "Perceived economic and managerial benefit" (28% spread), is linked by the statements reflecting the dimensions of the impact of tourism on the environment, tourism planning, tourism management, and society's impact on tourism.
The second factor, "Perceived demand for environmental sustainability", constituting 14.5% of the spread, linked 5 statements reflecting the dimensions of the impact of tourism on nature, the country's natural environment, the improvement of the country's envi-ronment for future generations, positive environmental ethics while promoting tourism development in the community, and the benefit of tourism development while preserving animals and their habitats.
The third factor, "Increased community participation and visitor satisfaction", constituting 11.3% of the spread, combined 3 statements reflecting attitudes toward sustainable participation of communities and visitor satisfaction, i.e., tourism decision making, regardless the origin, full participation in decision making regarding the attractiveness of tourism and country to the visitors.
The fourth factor, "Perceived social impact", which constitutes 9.5% of the spread, combined 3 statements reflecting how tourism and tourists influenced respondents' personal/social life and its quality.

Statistical Types of the Youth According to the Attitudes toward Sustainable Tourism Development
In order to divide the respondents into groups according to their attitudes toward sustainability, a statistical classification of the respondents was made.Cluster analysis was used for classification.Since the number of researched and classified objects is rather high, the cluster analysis of k-means (k-the average) was selected.The determined cluster structure was revealed by the square lines.
The typology of the subjects has been carried out according to four subscales, distinguished during the factor analysis.Considering the dynamics, the division of all the respondents into three clusters is the most informative and most easily interpreted graphical expression, as presented in Figure 4.
The second factor, "Perceived demand for environmental sustainability", constituting 14.5% of the spread, linked 5 statements reflecting the dimensions of the impact of tourism on nature, the country's natural environment, the improvement of the country's environment for future generations, positive environmental ethics while promoting tourism development in the community, and the benefit of tourism development while preserving animals and their habitats.
The third factor, "Increased community participation and visitor satisfaction", constituting 11.3% of the spread, combined 3 statements reflecting attitudes toward sustainable participation of communities and visitor satisfaction, i.e., tourism decision making, regardless the origin, full participation in decision making regarding the attractiveness of tourism and country to the visitors.
The fourth factor, "Perceived social impact", which constitutes 9.5% of the spread, combined 3 statements reflecting how tourism and tourists influenced respondents' personal/social life and its quality.

Statistical Types of the Youth According to the Attitudes toward Sustainable Tourism Development
In order to divide the respondents into groups according to their attitudes toward sustainability, a statistical classification of the respondents was made.Cluster analysis was used for classification.Since the number of researched and classified objects is rather high, the cluster analysis of k-means (k-the average) was selected.The determined cluster structure was revealed by the square lines.
The typology of the subjects has been carried out according to four subscales, distinguished during the factor analysis.Considering the dynamics, the division of all the respondents into three clusters is the most informative and most easily interpreted graphical expression, as presented in Figure 4.The first group contains 4.4% of the subjects, the second contains 71.5% of the subjects, and the third contains 23.4% of the subjects.
Cluster 1-indifferent to sustainable tourism development type.This type involves 4.4% of the youth.The youth of this type may be considered as representing a neutral or The first group contains 4.4% of the subjects, the second contains 71.5% of the subjects, and the third contains 23.4% of the subjects.
Cluster 1-indifferent to sustainable tourism development type.This type involves 4.4% of the youth.The youth of this type may be considered as representing a neutral or indifferent position regarding the sustainable development of tourism.All evaluation indexes of subscales identified during factor analysis are low.They are indifferent to the policy and benefits of tourism and they are rather neutral to sustainable environment and the economic and social benefits of sustainability.The idea of sustainability is complex to this group, and they perceive sustainability in tourism with skepticism.
Cluster 2-socioeconomic type.This type involves the biggest group of the youth in terms of sustainable tourism (71.5%).The youth focus on long-term economic welfare of the region that can be achieved by effective management, planning, and active societal participation in implementation of tourism policy.The members of this group consider sustainable tourism as an important social and economic aspect (low evaluation in the graph of perceived social impact means the opposite-it shows a high position, since the statements of this factor contained a negative connotation).
Cluster 3-balanced type.This type contains 23.4% of the respondents.All evaluation indexes of subscales identified during factor analysis exceed the average.The young people in this group are searching for the balance among all the aspects of sustainable tourism development.

Conclusions and Discussion
Tourism has experienced a significant growth during the last several decades.However, it has failed to follow the model of sustainable development and to respond to the socioeconomic and environmental challenges [78].The COVID-19 pandemic has disrupted the sector, almost bringing it to a standstill.The scale of the pandemic calls us to rethink and reshape the patterns of tourism development.Considering that the youth are regarded as the trendsetters in the global tourism market, this study aims to analyze the attitudes of youths towards sustainable development and their expressed behavior.
The expressions of sustainable behavior among the respondents was measured by grouping the statements related to self-evaluation.According to the research data, the respondents are mostly sustainable in their daily routines (buying products and goods, using household appliances, saving water resources, increasingly using the reusable bags when shopping).Unfortunately, weak sustainable behavior is noticed while travelling, in selection of means of transport, or using second-hand or recycled items (clothes, equipment).The results of the study revealed the need for more active dissemination of information and involvement of young people in achieving the goals of sustainable tourism.The participation of young people in non-governmental organizations, online platforms, or networks developing the idea of sustainable tourism could make a significant contribution to a positive outcome.
Amidst the COVID-19 pandemic situation, young people consider that the main challenges facing sustainable tourism today are the following: the amount of waste and pollution (especially during COVID-19); the use of non-renewable and limited resources; the impact of tourism on biodiversity and on natural and historical heritage; climate change.It is interesting that male respondents attribute the greater challenges to the development of sustainable tourism not to climate change (as prevailed in the assessment overall) but to weak governance and a lack of coordination between the public and private sectors, and poor quality of services offered by local tourism.
This paper applies the Sustainable Tourism Attitude Scale (SUS-TAS) and provides empirical evidence that could help to increase the involvement of youth in the development of sustainable tourism.According to research results, the respondents' attitudes toward sustainable tourism development are mainly related to the economic and managerial dimensions.Managerial contributions, such as well-coordinated sustainable tourism planning, assurance of the highest quality of tourism business services that would meet visitors' needs, and leadership, according to the respondents, can lead to the high economic benefits in sustainable tourism.The low evaluation of some statements, such as "Tourists in our country disrupt my quality of life", "My quality of life has deteriorated because of tourism in our country", "Our country's natural environment is being protected now and for the future by the tourism industry", shows that young people have positive attitudes toward tourism and care about tourism sustainability.There is an obvious desire among young people to be involved in tourism development and to participate in decision making.
This study employed a cluster analysis method, which allowed us to distinguish the statistical types of youth according to the youth attitudes towards the development of sustainable tourism and the expression of sustainable behavior.The identification and qualitative specification of the statistical types, as well as the determination of the percentage of these groups in the population and the focus on the very specific and real youth types, is important in the process of development of youth attitudes towards sustainable tourism and strengthening of sustainable behavior.The study identified and described the following existing statistical types among the youth population.
According to the expression of sustainable behavior of young people, the following types were identified:

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Expressed sustainable behavior type (18.4% of young people): This type of the youth exhibit sustainable behavior in all areas.They strive for the sustainable use of water and electricity and behave sustainably when shopping and traveling, etc.

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Oriented toward sustainable behavior type (50.6% of young people): People of this type are more neutral in terms of sustainable travel, are not particularly economical when shopping, but are likely to buy ecological goods, pay attention to sustainable use of equipment in the household, and save electricity and water resources, etc.

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Indifferent to sustainability type (31% of young people): This type of young people is skeptical about sustainability and is indifferent to sustainable behavior.
According to the youth attitudes toward the development of sustainable tourism, the following types were identified:

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Indifferent to the development of sustainable tourism type (4.4% of young people): This type of young people is indifferent to tourism policy and benefits; they are neutral in addressing environmental sustainability issues and in terms of economic and social benefits of tourism, and they are skeptical about the development of sustainable tourism.

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Socioeconomic type (71.5% of young people): This type of youth is focused on the longterm socioeconomic wellbeing of the region, which can be achieved through efficient management, tourism planning, and active public participation in the implementation of tourism policy.

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Balanced type (23.4% of young people): This type of young people seeks a balance between all aspects of sustainable tourism development and sees the need to develop sustainable tourism in ecological, economic, and social aspects.

Figure 1 .
Figure 1.Expression of sustainable behavior of the youth (N = 1085).

Figure 1 .
Figure 1.Expression of sustainable behavior of the youth (N = 1085).

Figure 2 .
Figure 2. The typology of the respondents according to the expression of sustainable behavior: 5always, …, 1-never (the model of three clusters) (N=1085).

Figure 4 .
Figure 4.The typology of the respondents according to their attitudes toward sustainable tourism development (the model of three clusters) (N=1086).

Figure 4 .
Figure 4.The typology of the respondents according to their attitudes toward sustainable tourism development (the model of three clusters) (N = 1086).

Table 1 .
Expression of sustainable behavior of the youth: results of factor analysis (KMO = 0.90, total variation 58.2%).

Table 2 .
The results of factor analysis of youth's attitudes toward sustainable tourism development; SUS-TAS scale (KMO = 0.91, total variation 63.3%).