*3.1. Population*

Generating greater than half of the yearly international arrivals, Europe represents the world's largest outbound region with respect to tourist flow [66]. Therefore, tourists aged 16 or over who, within the last two years, had gone abroad and who had made use of the Internet to plan their trip were the target population for this research. Tourists from the 18 major European countries, in tourist terms, were utilized for this study: Germany, Austria, Belgium, Denmark, Spain, Russia, Finland, France, Netherlands, Ireland, Italy, Luxembourg, Norway, Poland, Portugal, United Kingdom, Czech Republic, and Sweden.

## *3.2. Sample Selection*

This research was progressed through the use of a computer-assisted web interview (CAWI). A sample from the 18 countries was considered and was yielded from a database of panelists residing in each of these countries. It was to maintain the representativeness of the sample with respect to the population of each country. In order to achieve this, a random selection of the sample was undertaken, with this being based on the variables of stratification of the geographical area and province, on the one hand, and of the criteria of gender and age, on the other. Participation in the research by the selected sample was sought by sending them a personalized e-mail, with a personalized link being embedded in the e-mail that led them to an online survey. To achieve the expected quantity of completed surveys, two reminders were sent during the three months of fieldwork in the countries so as to encourage response. This culminated in the final sample consisting of 28,947 tourists.

Visits to the Canary Islands (Spain) was the focus of the analysis of the results, in particular with respect to the sustainable perceived image of this destination. In addition to the reason of convenience, the Canary Islands were chosen as the specific case due to it being a leading destination in Europe which enjoys a well-known brand throughout the continent. Given that it receives approximately 15 million tourists annually and has a complex economic ecosystem [7], these are factors which make it a perfect subject for consideration of the topic of sustainability. One of the 17 autonomous communities of Spain, the group of Canary Islands is formed as an archipelago located in the Atlantic Ocean.

Island destinations face specific challenges regarding tourism development [67]. The Canary Islands are highly relevant as a place of research, due to steady discussions about tourism development and growth [68] and the islands' character as an experimental zone for sustainable tourism in the context of an overflowing capacity of tourism growth [69]. Thus, sustainability in the Canary Islands destination has been the subject of a grea<sup>t</sup> amount of recent studies [70–73].

#### *3.3. Questionnaire, Quality Control, and Data Analysis*

The questionnaire was translated into the languages of each of the 18 countries. The survey was undertaken once the questionnaire had been pre-tested in the languages of the potential tourists and questions that had raised di fficulties in comprehension had received pertinent corrections. Upon completion of the necessary programming, the online system undertook a review of all of the conducted surveys. This included detecting the amount of time that respondents had taken to complete the survey, and any survey answered in less than 5 minutes was deemed as not valid. A binomial logit analysis was performed after completion of the fieldwork. A logit model based on the theory of random utility was chosen for this research. In utilizing this model, robustness in the estimated results is guaranteed, along with fulfilment of the properties of the conventional utility functions as established by the theory of the consumer.

With respect to the variables included in the model, tourists were invited to answer how sustainable they perceived the Canary Islands destination. A score of 1 indicates very unsustainable and 7 indicates very sustainable. For the statistical treatment of this variable, following the study of Almeida-Santana and Moreno Gil (2018) [7], it was necessary to dichotomize it, understanding that tourists who marked a 6 or 7 out of 7 were considered to perceive the destination as sustainable, while we understand that those who gave values between 1 and 4 do not perceive the Canary Islands destination as sustainable. Table 1 shows the description of all the variables included in the estimated model.


#### **Table 1.** Description of the variables included in the model.
