Measuring sustainable tourism: a state of the art review of sustainable tourism indicators

Abstract

In this introduction to the special issue, we identify the key tensions underpinning the challenge of developing indicators of sustainable tourism, and use the papers submitted to the special issue to exemplify these tensions. The paper questions why it is that we need to measure sustainable tourism, the risk of becoming too focussed on measurement itself and losing sight of what is really important to sustainability. We consider who it is that should be undertaking the measurement of sustainable tourism and offer evidence of the way that societal power can be rebalanced by the kind of research inclusivity that controlling data collection brings. Determining the spatial boundaries has been a long-held tension between wanting data specificity and achieving wider comparability and engagement from policy makers and other stakeholders, while technological and methodological advances may allow for more progress to be made in addressing the weaknesses of measuring sustainable tourism. The paper questions whether indicators have led to any significant policy change, or whether the changes that have come are the result of indicators serving to create more sustainably literate stakeholders, more informed discussions and so a climate more receptive to taking decisions in support of a more sustainable tourism industry.

Keywords:

• Indicators
• measurement
• destinations
• policy evaluation
• monitoring

Introduction

James Scott’s influential text “Seeing Like a State” argues that planned social order relies upon the standardisation and collection of data that can then be made portable for examination, evaluation and action (Scott, 1998). Scott gives an extended example of how measuring the different kinds of trees in forests in Europe enabled the re-planting of forests to be easier to manage and more productive. Managers were able to understand what trees the forest comprised and so to manage the forest from a spreadsheet without even the need to visit the sites. The collection of more data made the task of managing the forest easier, but it also began to change the natural aesthetic of the forest as further intervention enabled greater productivity. Scott observes that the collection of data to manage the forest “…illuminates the dangers of dismembering an exceptionally complex and poorly understood set of relations and processes in order to isolate a single element of value” (Scott, 1998, p. 21).

Despite the warnings of Scott, European and international agencies (such as Eurostat-CE, ESPON-EU, TourMIS-ECM, UNWTO or OECD) have led the drive to produce and collect data on the sustainability performance of the complex social phenomenon that is tourism. Arguably the environmental and socio-cultural data are still poor quality, (Modica et al., 2018) whereas the economic data are higher quality, regularly updated and easily available, reflecting the dominance of the economic rationale for tourism development (Bošković et al., 2020). One of the first key texts to comprehensively consider measuring the sustainability of tourism was the UN’s “Practical Guide to the Development and Use of Indicators of Sustainable Tourism” (UN, 1996) and their latest report nearly a quarter of a century later (UNWTO, 2020) demonstrates now the proliferation of schemes and systems used to measure the impacts and contributions of tourism to the economy, society and the environment.

This special issue seeks to publish papers from authors currently using indicators and to expose these for critical comment. This introduction takes the opportunity to re-consider fundamental questions about why do we seek to measure sustainability and what are the risks of doing so. It also asks important questions of who should be measuring performance, what should we measure, how and at what scale should we be measuring. These are the recurrent themes presented in all the papers that comprise this special issue and the positions taken by the different authors on these issues vary, rendering it impossible to draw a consensus on the preferred, or dominant approach. However, while the more absolutist UNWTO (2020) search for a standardised framework to measure sustainable tourism continues, the issues raised in the papers in this special issue, the arguments for different approaches, and indeed the recognition of the value of difference demonstrate the value of being able to critically explore this topic and consider the future role of indicators in the pursuit of more sustainable tourism.

Why measure sustainable tourism?

The established answer for why should we seek to measure the sustainability of tourism is that the data produced allows for the better management of the industry and destinations. One of the co-editors of this special issue (Miller, 2001), and Butler (1999) have both argued that indicators help to make tangible the fuzzy concept of sustainable tourism through identifying key factors of change, their evolution, and potential threats (James, 2004). Schwab and Mallaret (2021) coin the phrase “quantum politics” to explain how the world is becoming more complex and connected in ways that are difficult to comprehend. In that context, indicators are attractive as they promise a heuristic to managing a complex problem. Sustainable Tourism Indicators (STIs) simplify, clarify and aggregate information for policymakers, which enable evidence-informed decisions and more effective actions (UN, 2007). Accordingly, they have become widely accepted as a key tool to guide sustainable development in tourism and Marinello et al. (2023) show how the topic has garnered a great deal of interest from academics and researchers.

By contrast, Porter (1995) argues that we seek to measure and quantify phenomena in order to overcome the distrust that exists towards authority and decision-makers. The objectification that comes from measurement de-politicises an outcome, creates trust and enables the decision-maker to operate without their expertise being questioned or challenged. Porter (1995) describes how trust in public experts has come to be in short supply, and the time necessary to develop trust is no longer available in an instantaneous world. Pertinent perhaps to tourism, Porter (1995) argues that newer and weaker disciplines lean more heavily on statistical methods as the authority of the expert is most in question. Hence, subjectivity creates responsibility for the conclusions reached and pressure on the experts to explain their conclusions.

The clear danger with this argument is that it pushes management towards those elements of a problem that can be measured. If the aphorism “what gets measured gets managed” is indeed true, then there are risks from the sequitur of this statement that “what doesn’t get measured, doesn’t get managed”. The viscious cycle potentially extends by de-skilling the role of decision-making and subordinating it to the role of data manager. Porter (1995) cites how medical doctors were initially concerned that the introduction of instruments to measure the health of their patients would diminish their own authority in reaching a diagnosis. Today, we would clearly expect a medical doctor to employ measurement devices where necessary to help with understanding a patient’s health, yet the unease expressed at receiving a diagnosis purely from an artificially intelligent evaluation of data speaks to the importance of the intervention of human judgement. Delacroix (2017) writes of the risk of “moral atrophy” that comes from humans outsourcing complex decision-making to artificial intelligence, and the subsequent inability to use weakened experience if technology fails.

If measurement is important to either improve trust, or to fuel evidence-based decision-making, then the methods of measurement need to be accepted as rigorous and validated by appropriate scientific bodies. Hence, the proliferation of papers on indicators, and the search for the perfect measurement system. The risk with focussing on the measurement system is that it moves us further away from the objective, which is to improve the sustainability performance of tourism. The American philosopher Nguyen (2021) discusses in detail how Twitter has gamified communication in the same way that fitness apps have gamified exercise. The use of “thin metrics” such as “likes”, “re-tweets” or heart rate, and calories judge the merits of a contribution to a conversation, or a bicycle ride, but do not strike to the purpose of having a conversation, or going for a ride and the deeper pleasure these bring. Nguyen (2021) fears “value capture” when our values undergo a long-term simplification because of the external metrics used by institutions and technologies. Continuing this challenge to its end point, the German philosopher Theodor Adorno was asked to conduct a study on the impact of radio and observed, “When I was confronted with the demand to “measure culture”, I reflected that culture might be precisely the condition that excludes a mentality capable of measuring it” (Adorno, 1969, p. 347).

Yet, with tourism, and particularly with sustainable tourism, perhaps the development of sustainability metrics expands the values we are concerned with because our starting point of focussing only on economic benefit is so impoverished? In “The impact of sustainable tourism indicators on destination competitiveness: the European Tourism Indicator System” by Xavier Font, Anna Torres-Delgado, Gloria Crabolu, Jesus Palomo Martinez, Joseph Kantenbacher and Graham Miller the authors argue that the lack of evidence of impact of sustainable tourism indicator schemes comes from an unrealistic understanding of the way in which policies are made. This paper evaluates the impact of sustainable tourism indicators on destination competitiveness with reference to the European Tourism Indicator System (ETIS), a scheme funded by the European Commission to address the evidence gap in tourism policy making. The paper uses the concept of absorptive capacity to assess the extent to which destination management organisations implement and use sustainable tourism indicators to make policy decisions. Through a process of interviews, document scraping and focus groups the paper shows that DMOs have used indicators to acquire knowledge and assimilate it into the organisations, but there has not been a transformation of the practices, or really exploited the knowledge from the indicators.

Yet, indicator schemes do produce benefit in changing the context of discussions and bringing a wide diversity of stakeholders together, which can subsequently enable more sustainable policy decisions to emerge. Maria Laura Gasparini & Alessia Mariotti in their paper “Sustainable tourism indicators as policy making tools: lessons from ETIS implementation at destination level” consider the different benefits that developing systems of indicators can bring, beyond just enabling an understanding of the performance of a destination. The authors review the impact the European Tourism Indicator System has had in terms of how it had been employed to directly affect and justify decisions, as well as to raise awareness about sustainability more broadly. Using this framework of impact, the paper assesses the effectiveness of the ETIS approach in a number of destinations across Europe who tested the system. The authors conclude that while there is limited evidence of the indicators being used to directly change policy, there is evidence of the connection between indicators and the policy making context. They believe that the system should have adopted more performance indicators, along with targets, in order to allow destinations to evaluate whether or not the destination was moving towards, or away from the desired outcome. This tension reflects the need to strike a balance between destinations claiming agency over the process and asserting local requirements, versus the value of setting minimum expected standards across common indicators. The authors argue that the indicators do help with generating wider learning about sustainability and the process for developing the indicators enables awareness raising, team-building and a “subtler influence”, which can be considered as a pre-condition for other benefits to be achieved.

Similarly, in “Monitoring sustainable management in local tourist destinations: performance, drivers and barriers” by Anna Torres-Delgado, Francisco López Palomeque, Berezi Elorrieta Sanz & Xavier Font Urgell the paper shows how the use of sustainability indicators is still not common amongst decision makers, with traditional economic indicators dominating. However, the paper does detect an increasing importance of sustainability in tourism and the reflection of this in local destination planning. The authors make three further valuable contributions by explicitly trying to focus the indicators on the requirements of policymakers to effect change, identifying the value of indicators to develop momentum for change and acceptance of a new framework for thinking, but also recognising that indicators should never be seen as an end in themselves, and should always seek to initiate, rather than conclude a conversation.

Who should measure sustainable tourism?

Chalmers and Glasziou (2009) argue that if the research process can be broken down into four stage; asking the right questions, using the right methods, using accessible media for publication of results and ensuring results are reproducible, then at each stage 50% of research is wasted. The authors were addressing themselves to research in the field of biomedicine, but the challenge seems perfectly apt to the social sciences as well. If we are to begin to make better use of the resources we do have to commit to research, then this must begin with ensuring we ask the right questions. This comes from ensuring that the intended audience and user of the findings are involved in the design of the study, and potentially also the collection of the data.

In Liberating sustainability indicators: developing and implementing a community-operated tourism sustainability indicator system in Boga Lake, Bangladesh, by Md Saiful Islam, Brent Lovelock & Willem J. L. Coetzee the authors expand the notion of community-based tourism to consider the value of the community being involved in the design of indicators to assess the success of the tourism investment. This involvement seeks to overcome the commonly seen problem of funder-led projects monitoring the elements of the project they are interested in, but without capturing whether the project really delivers the changes that the community wishes to see. While examples are increasing of communities becoming involved in the design and development of the indicators, in this paper, the community also seek to take control of the collection of the data, operation of the indicator system independent of external agencies, and writing of the final assessment reports. The authors explain the inclusive research methodology that the community in Boga Lake, Bangladesh go through to formulate the indicators. Perhaps most interesting in this paper is the way in which the community recognised that collecting data and producing reports was the most effective mechanism to negotiate with local authorities and other stakeholders, and so demonstrating recognition that to be effective in evidence-led debates requires the acquisition, and ownership of evidence. The approach of the community is also perhaps a tacit understanding that the selection of indicators, collection of data and production of reports is not a neutral process and is one that is better to be controlled, rather than used against them.

While Islam et al. (2021) focus on the benefit to sustainable tourism of having local communities involved in indicator development, Ana Moniche & Inmaculada Gallego in Benefits of policy actor embeddedness for sustainable tourism indicators’ design: The case of Andalusia, focus on the benefits, and challenges, from having policymakers involved in the process. Echoing the findings of Ivars-Baidal et al. (2021), the authors highlight the way in which governance concerns have been under-recognised in the development of sustainable tourism indicators. The paper draws on the example of Andalusia in Spain, which developed a system of measuring the impacts of tourism once it received delegated authority for setting the strategy and management of tourism. This change combined with the region’s improved production of data, and the underpinning importance of tourism to the regional economy to give it the ability and motivation to develop a system of monitoring for tourism in the region. The authors are able to present the process for developing this regional system and focus on the role of including policymakers within the process. They conclude that policymakers add to the process of indicator development by their understanding of the policy making process and how data will be used. They further identify the more strategic use of data to support policy decisions, as well as introducing several policy specific indicators. Yet, the involvement of policymakers can also be a problem because of conflicting timelines between their more immediate interests and the needs of sustainability, which operate on longer time horizons. The authors also reflect on the always thorny issue of balancing the value of creating a common set of indicators that can be used to compare and create benchmarks, with the loss of local specificity, empowerment and sense of agency that comes from a common set of indicators being applied from outside the region.

Another alternative to local residents and regional policymakers designing and collecting the data is the expert panel. Concepción Foronda-Robles, Luis Galindo-Pérez-de-Azpillaga & Alfonso Fernández-Tabales in Progress and stakes in sustainable tourism: indicators for smart coastal destinations use an expert panel to compile a system of 30 indicators for a smart coastal destination. This system aims to enable sustainability to be assessed and compared across time and space, using the concept of Territorial Intelligence that focusses attention on the physical impacts of tourism on a place. The paper takes 14 coastal destinations in Spain as a case study to apply the indicators to. Recognising the weaknesses from consulting any one group of stakeholders to design a system of indicators, leads Ionela Mihaela Damian, Enrique Navarro-Jurado & Francisco Ruiz in their paper, Involving stakeholders in the evaluation of the sustainability of a tourist destination: a novel comprehensive approach to design an approach that can achieve the participation of a range of stakeholders, not just in the development of a set of indicators, but also in the determination of the appropriate level of target and evaluation of performance against these targets. The authors stress the growing need for such participatory processes in order to be able to achieve a wider, multidisciplinary approach to the study of sustainable tourism. The paper seeks to establish the relationship between stakeholders, and then calculates a “power index” to weight the views of each stakeholder depending on their degree of influence and centrality to decision making in the destination. The stakeholders themselves are asked to weight the importance of different indicators, which creates a possible calculation of their weighting multiplied by the power index of each stakeholder. While the creation of a power index perpetuates the understood imbalances within any destination, it does also reflect the reality that there are voices that are more influential than others in the creation of any system. The paper’s power index makes explicit those weightings and the consequent impact of the views of certain stakeholders.

Where to measure?

Closely linked with thinking about who should design and measure sustainability, is the question of the spatial scale at which data are collected. STIs can be applied on multiple scales, as different spatial units play a significant role in planning and managing sustainability issues, yet clearly destinations do not exist in isolation and are embedded in a particular social, economic and territorial context. The earlier section focusses on thinking about why we measure, in recognition that each context will potentially have a different answer to that question. Both the spatial scale (international, national, regional, local), as well as the geographical context (coast, mountain, cities, rural areas) will influence why indicators are necessary, but also the way they are chosen, the fit and the availability of data.

Balas and Abson (2022) and Torres-Delgado and Saarinen (2014) both identify sustainability indicator schemes in tourism at all territorial levels, but highlight a predominance of such schemes applied to local and regional scales. Monitoring the sustainable development of tourism at the local level has the advantage of focussing attention where tourism actually takes place (Choi & Sirakaya, 2006; James, 2004; Logar, 2010; Torres-Delgado & López Palomeque, 2014; Vera & Ivars, 2003; Vila et al., 2010). Local level schemes offer high flexibility and adaptability of the STIs but, at the same time, lack standardised and harmonised approaches to compare performance (Batista e Silva et al., 2018; Marinello et al., 2023). This search for specificity has driven greater disparity in methodologies of collection, as well as in quality of STIs.

Currently, in an attempt to provide methodological guidance and data quality and comparability, the UNWTO (2021), in collaboration with the UN Statistics Division, has developed their “Statistical Framework for Measuring the Sustainability of Tourism” (SF-MST) programme to measure the impacts and contributions of tourism to the economy, society and the environment. Several countries have carried out pilots to test the SF-MST in terms of both relevance and feasibility, as well as to provide lessons and novel or pragmatic solutions encountered on the ground. Alongside this initiative, UNWTO has also launched the International Network of Sustainable Tourism Observatories (INSTO), which directs destinations towards issues that need to be monitored in order to improve their performance towards sustainable development in tourism. By contrast, a broader, regional level scheme, particularly those that draw on existing indicators of official statistics sources, such Eurostat (see Alfaro Navarro et al., 2020; Bertocchi et al., 2021) overcomes the challenges of data availability and comparability, but it risks concealing local contextual differences, needs and levels of tourism development. Further, the regional level of policymaking can be distant from the local government, thus the resulting scheme may allow for affordable measurement of sustainability in tourism, but it is not useful for the purpose of local management.

The issue of where to draw boundaries around what we are measuring has always been a keen problem for indicator development. This speaks directly to the tension between the availability of data, which usually improves with higher and larger levels of government, the specificity of data, which typically improves the more local the level of analysis and the benefits to be had from comparing data across destinations. An approach adopted to reconcile the tension of geographic specificity and data comparability is to create common, core indicators as well as site and destination-specific indicators (Biermann et al., 2017; European Commission, 2016; Kanie & Biermann, 2017; Lu et al., 2015; UNWTO, 2004). However, this “good practice” demands a cross-disciplinary, and cross-jurisdictional approach to implement integrative policies (Pan et al., 2018), thus involving different departments and levels of government. Yet, tourism policies are often too fragmented (limited perspective of a broader context) or too general (difficult to meet the local needs). These limitations reveal themselves in the STIs, which fail to strike a balance between context-dependent specificity and comprehensive relevance (Torres-Delgado & Saarinen, 2014).

Dario Bertocchi, Nicola Camatti, Luca Salmasi & Jan van der Borg in Assessing the tourism sustainability of EU regions at the NUTS-2 level with a composite and regionalised indicator, provide a helpful review of the choices available, and dilemmas present, to those who design and develop systems of indicators of sustainable tourism. The solution proposed by these authors is to focus on developing regional level indicators as a compromise between data availability, comparability and specificity challenges. The authors adapt the World Economic Forum’s Tourism and Travel Competitiveness Index to the regional context, but because of its global origins, the indicators enable destinations to be compared, whilst also the calculations are based on pre-existing data and link to the national level indicators. The authors stress the importance of indicators enabling policymakers to have confidence in using the data to evaluate performance and make decisions, something they believe is enhanced through having indicators that are drawn from national sets and enable comparisons across territories. Indeed, the authors develop their research further to create a dashboard that allows users to visually understand the relative performance of destinations across Europe, based on the regional indicators selected. The value of these comparisons is also something Maria Laura Gasparini & Alessia Mariotti identify in their study on those destinations who had engaged with ETIS. Indeed, facilitating a web-based comparison across destinations, which can only come from a degree of top-down design of common indicators, had been one of the original aims of the ETIS (?)project.

By contrast to Moniche and Gallego (2022), in Identifying the sustainability indicators of overtourism and undertourism in Majorca, by Macià Blázquez-Salom, Magdalena Cladera & Maria Sard the authors view the challenges of a destination as being so particular to the destination, that data collection, and the measurement instrument itself, needs to be site specific to capture all the nuances. They take the example of Majorca (Spain) to examine the way tourism indicators could contribute to monitoring the problems of both over, and under-tourism on this most famous of tourism destinations. The paper considers the way the collection of data can help to define a concept, such as overtourism and undertourism, where it is perhaps too easy to jump to the conclusion that this is all about numbers generating negative experiences for residents and tourists alike. The method of achieving local stakeholder input varies from other papers, but the objective remains the same to enable thinking in terms of what the problem is that needs to be solved, and then think about how to measure this, rather than understand the problem in terms of the data available. The paper stresses the acute need for Majorca to reimagine its tourism industry post-Covid and not simply to return to the previous model of tourism. If this is to happen, then the system by which we measure tourism’s impacts, both positive and negative, must also change and it can no longer be acceptable to argue that the data simply do not exist. The authors identify interesting indicators such as the number of strikes and protests as a metric for social conflict or the degree of uncivil behaviour experienced by residents.

The local level is also the focus for Anna Torres-Delgado, Francisco López Palomeque, Berezi. Elorrieta Sanz & Xavier Font Urgell in Monitoring sustainable management in local tourist destinations: performance, drivers and barriers. Here, the authors present the example of the use of a set of indicators developed to assess overall sustainability, and performance of tourism across the province of Barcelona (Spain). These indicators were developed from the ETIS framework, but identify the local level as being where the different stakeholders come together, and where most of the decision-making takes place. The research recognises, as have many of the papers in this special issue, that there are significant problems with finding data of sufficient abundance, quality, specificity and comparability in addition to the lack of time and human resources available to collect the data. The paper sets itself the task of developing a set of indicators that can apply across the 38 destinations within the province of Barcelona and can enable both longitudinal comparisons for destination against their own performance, as well as benchmarking across destinations.

In Considering regional challenges when prioritising tourism policy interventions: evidence from a Mediterranean community of projects, by Spyros Niavis, Theodora Papatheochari, Tonia Koutsopoulou, Harry Coccossis & Yannis Psycharis the authors discuss the role of indicators in setting baseline understanding of a place, in order to measure change caused by a policy intervention. This application of indicators is different from that of the other papers in this special issue, as this paper applies the indicators in order to be able to determine the effectiveness of specific funded projects in achieving their objective of promoting sustainable tourism in Europe. The paper identifies the preference in the literature for indicators that enable national comparisons, rather than more regional comparisons because of the lack of quality of data and comparability of indicators. Even with the desire to adopt indicators where there was complete availability of data, it was still not possible to collect full data sets for each of the 41 coastal regions in the scope of the study. However, the results allow the authors to present conclusions showing the destinations with the greatest need for further policy intervention, and to cluster these destinations to try to identify similarities between them.

How and what to measure?

The quality and ability to update data are critical to have meaningful indicators, and yet severe difficulties arise when measuring sustainability. Sustainability data, in general, have improved in recent times, but we have not seen enough of these advances transfer to the tourism sector where the completeness and comparability of sustainable tourism indicators are still poor (Alfaro Navarro et al., 2020; Buckley, 2012; Font et al., 2021).

The capability to produce data is very often highly limited in a destination and dependent on its human and financial resources. UNWTO (2020) points out the problem of funding, but also the lack of methodological guidance and technical skills, as important challenges faced by destinations in this regard. Further, available data responds to pre-identified problems framed in pre-conceived priorities, thus rethinking what is important is difficult (Font et al., 2021). Without a resolute determination to remember why data are being collected there is the likelihood of the choice of STIs being driven by what can be measured, rather than what needs to be measured (Alfaro Navarro et al., 2020; Mitchell, 1996; White et al., 2006). Hence, many well-intentioned STI contributions demonstrate difficulty putting into practice outcomes from lengthy data collection programmes (Budeanu et al., 2016; Buckley, 2012). As an example, the literature shows too many case studies where established sets of pre-existing indicators are simply applied to new contexts (Alfaro Navarro et al., 2020).

New technological tools could be extremely useful to respond to data production difficulties. Indeed, the new paradigm of smart destinations is leading to the increasing use of data and information and communication technologies (ICTs) for monitoring and management. ICTs potentially enable both the collection of data in different ways, in an automated and real-time manner, but also the processing of larger and more innovative sets of data than has ever previously been possible (Rahmadian et al., 2022). During the covid epidemic the UK Office for National Statistics used traffic data and retail spend as effective lead indicators of potential outbreaks of the disease, reflecting that people refrained from going to work and shopping several days before they received results of a positive test confirming infection. Health officials were then able to mobilise resources in response to evidence of a hotspot developing, faster than had they waited for medical results to confirm sickness (Diamond, personal communication, 2021).

Yes, despite their great potential, very little evaluative research has been done applying big data and AI to measure and monitor sustainable tourism at a destination level (Balas & Abson, 2022). Big data in research is still challenging in data quality, data cost and privacy concerns while it often does not cover the whole sample, or the data are questionable (as in the case of online review data) (Li et al., 2018). Potentially highly useful data, such as mobile roaming or credit card transaction data, have their usefulness reflected in the price charged to access it, or are not made available at all (Rahmadian et al., 2022). Studies using artificial intelligence for statistical treatment of sustainability indicators require good technical expertise in computer science, compounding the already felt limitation of a lack of local resources capable of running an indicator scheme (see Lisi & Esposito, 2015; Zhang et al., 2015).

It is important to remember that tourism is a social activity and much of its impacts are on people. To this end, novel methods of collecting data should not automatically default to thinking about the role of technology. Drawing on wider and more diverse segments of society allows for richer sources of data, which become a new input into the system (Baggio et al., 2010) and creates a learning environment, stimulates discussion and leads to debate or consensus. Indicators operate in complex systems where continuous interactions between stakeholders affect the outcome of the policies. As a result, social learning is demonstrably embedded in the knowledge exchange that happens when developing measurements on the sustainable development of tourism (Farsari, 2023; Twining-Ward & Butler, 2002). In this way, new data contribute to open decision-making in public management, which is increasingly recognised as a “good governance” (Becken & Loehr, 2022).

In Sustainable tourism indicators: what’s new within the smart city/destination approach? by Josep A. Ivars-Baidal, J. Fernando Vera-Rebollo, José Perles-Ribes, Francisco Femenia-Serra & Marco A. Celdrán-Bernabeu, the authors examine how the emergence of smart tourism destinations hold the opportunity to influence the concept of sustainable tourism, and more specifically, the development of indicators of sustainable tourism. The smart cities approach has sustainability and data analytics as integral to it, so indicators of sustainability should be a natural element. Yet, the authors’ analysis of the review of international smart sustainability standards shows an absence of mention of tourism within these standards, and a consequent invalidation of these standards as making a contribution to measure sustainable tourism. They conclude that despite the conceptual integration and the many initiatives launched in practice, there has been little tangible achievement of sustainability in smart city destinations.

Despite the lack of actual contribution, based on their review of the respective literatures, the authors provide a very thoughtful set of recommendations for where the smart approach to city destinations could make a helpful contribution to the development of sustainable tourism indicators. These comprise reinforcing the importance of governance, accessibility, social inclusion, local heritage and identity as being important in guiding the process towards smart destinations, but also stressing the need for simplification of the understandability and number of indicators. The authors also see benefit to be had from greater incorporation of measures of technology and innovation, while developing indicators based on intelligence, marketing and digital information that facilitate the promotion of more sustainable behavioural patterns in the whole trip cycle, both from the supply and the demand sides. The authors conclude that there is a need to develop specific tourism indicators to integrate into the management of the interrelationships between the tourism activity and the urban quality of life in a smart destination of the future.

The paper by Brian Szuster, Mark D. Needham, Laura Lesar & Qi Chen in From a drone’s eye view: indicators of overtourism in a sea, sun and sand destination uses traditional evaluative surveys of tourists to establish perceptions of encounters, norms and crowding, but combines this with descriptive images from drones to determine actual use levels at the destination. In so doing, the researchers seek to better understand maximum capacity limits before tourists’ experience begins to diminish. Collecting data on actual usage levels is often difficult and expensive, resulting in sampling methods with their attendant risks. However, drone technology offers the opportunity to accurately and cheaply capture images of destinations, that facilitate the simple determination of numbers of tourists. The process is still encumbered by the manual task of counting tourists from the drone images captured, but here the authors highlight the potential improvements that can come from machine learning technologies and artificial intelligence to automatically detect tourists. The research shows that the data collected enables policy decisions to be made about acceptable levels of crowding and user perceptions, which leads naturally to management actions such as quotas, advanced bookings, fees or the promotion of alternative sites. The paper relates to a classic sun, sand and sea tourism destination, Kailua Beach Park in Hawai’i, which has been criticised for its growing popularity and as such, is typical of much beach tourism around the world.

An extension of the question of how to measure sustainability performance is the question of how to evaluate the data produced (Hunter, 1995). A target value or threshold values identifying desirable conditions should guide sustainable indicators for decision-making (Roberts & Tribe, 2008). However, establishing a reference condition is not fully unbiased and may result in different assessments depending on the selected criteria. Balas & Abson (2022) suggest that to avoid an arbitrary selection of targets, thresholds must be widely accepted and scientifically founded as well as consider sector-specific characteristics and be achievable under given conditions. Nevertheless, Crabolu and Amin (2020) warn about the difficulty of this task due to the differences across destinations and between assessment approaches. This disparity justifies the wide range of strategies to set sustainability targets. The majority of the experiences do not provide numerical representations or absolute targets, but a more directional approach based on (1) the progress made towards or away from a sustainability pre-condition (see Roberts & Tribe, 2008), (2) destination benchmarking (see Bertocchi et al., 2021, Bošković et al., 2020; Cobacho-Tornel, 2019; Torres-Delgado & López Palomeque, 2014) or (3) a combination of both by measuring the evolution of the destination regarding its sustainability and, at the same time, relativise its position with respect to other territories (see Blancas et al., 2018; Torres-Delgado et al., 2021). The few experiences setting quantitative limits are defined based on stakeholders’ agreements on what a sustainable destination looks like (see European Commission, 2016).

The paper Environment, logistics and infrastructure: the three dimensions of influence of Italian coastal tourism, by Andrea Ciacci, Enrico Ivaldi, Stefania Mangano & Gian Marco Ugolini uses a novel method of analysing publicly available data, the Mazziotta and Pareto Index, to understand the impact of indicators assessing tourism’s key drivers of environmental quality, logistics and infrastructure, on the overall performance of tourism along Italy’s coastal destinations. The analysis was conducted by examining 301 of the 314 seaside municipalities surveyed by Legambiente for the Guida Blu 2017, and from there compiled a composite indicator, derived from a host of constituent indicators. The paper enters into, and informs the debate over using aggregated, or composite indicators versus a dashboard style approach that instead reports each individual indicator. It recognises that as scientists, we will have preference for seeing raw data, but that for policy makers, the media and the public there is real appeal of a simplified score from a composite index. For Minguela (2022) the question is less about the form of the data, but more the timing, availability and ability to manipulate the data to help with decision making. While the search for a single metric to encapsulate sustainability is appealing, recognising that this leads to an over-simplification of our understanding takes us to the conclusion that we need better data, not instead to accept the over-simplification. Minguela (2022, p. 35) argues the solution “…requires understanding the differing objectives and preferences of decision-makers and providing them with accurate data, but also leaving room for incorporating individual viewpoints”.

Conclusions

Sustainable tourism needs effective governance, policies and evaluation tools to plan and manage its development (Bramwell & Lane, 2011; Pan et al., 2018). In this vein, there is a broadly agreement about the potential usefulness of the indicators as a flexible tool to assess and monitor territory development policies and strategies (Marinello et al., 2023). Many proposals of STIs have been built since sustainability arose as a target for tourism development (see Balas & Abson, 2022; Torres-Delgado & Saarinen, 2014) and the theoretical/conceptual approach to STIs is well-developed with their practical implementation tested in numerous destinations. However, important issues remain unresolved and there remains the need for further examples of destinations addressing the challenge of scale and data availability versus data specificity. There is also a need for much more work on how to utilise new technologies and collect and integrate innovative forms of data –especially around society and the environment. Important in this work is the need to think about why we are measuring, and not simply include data because they are available. To aid this consideration there is need for further work on how to adopt greater research inclusivity and incorporate a wider set of voices. There can be no doubt that a future world needs to be more inclusive, not less and more receptive to reversing, or at least levelling the understanding of who is the expert in a destination.

It is not unusual to end a review of a topic with a shopping list of further questions that need research. Ensuring the sustainability of research is an established part of our training and practice as an academy. Yet, a frequently cited refrain for inaction over sustainability has been the lack of data to inform decision-making. The last thirty years have developed a wealth of data and systems of how to measure the sustainability of tourism. We do not have a perfect system, but the article shows that this is never going to be the case, nor should it be something we aim for. A “one-size-fits-all” set of STIs is not possible, and the prolific and diverse production of STIs has created a “choice overload”, but we certainly now have a sufficient body of knowledge that if any destination is serious about wanting to measure its impacts, then they can design an appropriate system. Future work should go on gaining consensus about a global framework for sustainable tourism assessment without neglecting flexibility for adapting indicators to wide a range of contexts. The ETIS has set precedents for this, but ultimately the lack of institutional support from the EU dashed its opportunity to become the established framework. The forthcoming MST framework is a new opportunity to reinforce leadership and shared guidance on STIs.

Indicators have been mainly used to raise awareness about sustainability issues and gain consensus about tourism impacts, but poorly to promote better governance or to introduce sustainability as a priority for actual policies (McLoughlin et al., 2018; Modica et al., 2018). Indeed, sustainable development means transforming traditional patterns of consumption and focussing on the long term, which is clearly challenging industries such as tourism.

It is important to also reflect on the lack of progress on enhancing sustainability despite the gathering wealth of knowledge about the impacts of tourism. Global tourism is untenable at least in environmental terms (Sharpley, 2022), and there is little agreement on long term policies to advance sustainability in tourism (Miller, 2001). Difficult and unpopular decisions will need to be made, but the more well-informed through the knowledge, the easier it is to “disrupt the status quo” and encourage collaboration and integration of divergent views (Farsari, 2023). Yet, the ultimate objective of STIs is to influence policymaking for good and academic and professional contribution to measuring sustainability in tourism is still too focussed on the tool, and raising awareness rather than on its effect. There is no clear evidence that STIs are leading to making more sustainable decisions in planning and managing destinations. Therefore, much more work is needed on how decisions and policy are made, and crucially, what stops decisions from being made in order to understand what role data, measurement and indicators play in aiding this process.

Finally, what we cannot do is expect indicators to do the thinking for us. Metrics and data, in all their forms, allow us to develop our experience which we bring to each individual set of circumstances. There will be novelty and difference to every scenario in which a decision needs to be made about directions of travel and so there is an important evaluative role for experienced people to understand what the data are saying, and to respond appropriately. Our role as scientists is to ensure the debate about how to improve the sustainability of a destination is informed by relevant data, but also to be sure the debate does happen and we do not just proceed with a blind trust in numbers.

Acknowledgement

This paper has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska Curie grant agreement No 890281.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Graham Miller

Prof. Graham Miller is Professor of Sustainability in Business at the University of Surrey.

Anna Torres-Delgado

Dr. Anna Torres-Delgado is Marie Curie Research Fellow at the University of Surrey and Lecturer in Tourism Geography at the University of Barcelona.