Tourism and Sustainability in the Evaluation of World Heritage Sites , 1980 – 2010

At present, there are myriad concerns about tourism and sustainability at cultural and natural world heritage sites. Based on an analysis of 811 evaluations written between 1980 and 2010 by two official advisory bodies to the World Heritage Committee, this paper charts the timing and extent to which such concerns have become central to assessing the value of heritage sites. We find that, over time, issues related to tourism and sustainability expanded considerably in quantity and variety, and recommendations for managing and developing sustainable tourism became a routine feature of site evaluations. Despite the growing prevalence of such concerns, the conceptualization of sustainable tourism and related recommendations provided by the advisory experts remain somewhat ambiguous. Furthermore, our findings reveal regional disparities in the degree to which tourism is seen as a threat to the sustainability of heritage sites and in the likelihood that a state is considered a model of sustainable tourism.


Introduction
In 1972, the Convention concerning the Protection of the World Cultural and Natural Heritage, or World Heritage Convention, was adopted at the seventeenth session of UNESCO's General Conference [1].Building on key institutions in world society [2], the Convention's aims to identify, protect and preserve "cultural and natural heritage of outstanding universal value" have rapidly diffused throughout the world and achieved near universal acceptance in the decades since.Indeed, when the Bahamas ratified in 2014 it became the 191st State Party to adhere to the World Heritage Convention, furthering its status as the most widely accepted UNESCO convention [3].Yet just as the World Heritage List has expanded to include over one thousand cultural and natural heritage sites, the concerns and challenges associated with successfully preserving world heritage have multiplied as well [4].Among those concerns are the sustainability of an ever-expanding number of inscribed sites [5] and the social, economic, and environmental impacts of tourism on cultural and natural properties [6][7][8].Although the World Heritage Convention predates the concept of sustainable tourism, Labadi [9] suggests that it is implied in Article 4, which places responsibility with each state party to ensure the "presentation and transmission to future generations" [1].This brief statement highlights the difficult balance between preserving world heritage and making it accessible to the public.
Today, such concerns have been formally incorporated into UNESCO's World Heritage and Sustainable Tourism Program [10], as well as sustainable development initiatives [11], which seek to balance the interests of world heritage's diverse stakeholders.While efforts to promote sustainable tourism have inspired a great deal of scholarly analysis, debate, and even skepticism [12][13][14][15], this paper focuses on how and when issues of sustainability and tourism emerged in the world heritage arena as well as how concerns about these issues have changed over time.In particular, we highlight the role of two official advisory bodies-the International Council on Monuments and Sites (ICOMOS) and the International Union for the Conservation of Nature and Natural Resources (IUCN)-in assessing and articulating concerns about sustainability and tourism through an analysis of their evaluations of over 800 cultural and natural sites nominated for inscription on the World Heritage List.Our approach is inspired, in part, by institutional [16] and "cultural wealth" approaches [17] to global analysis in sociology, which we briefly describe below.
Many observers have understandably criticized heritage tourism as either a profit-making tool of the tourism (or heritage) industry; a means of identity construction and self-aggrandizement for nation-states that reflects elite interests [18][19][20]; or a Eurocentric imposition by Western countries and international agencies [21][22][23].Among other things, such efforts to commoditize, politicize, or universalize heritage are seen as a threat to the authenticity of cultural and natural properties [24][25][26].Yet scholars have also shown that inscription on the World Heritage List is neither a guaranteed boon to tourism [27][28][29] nor a process that is always driven by elites [30].Other studies highlight the problems with conceptualizing the tourism industry as a monolithic entity [31] and demonstrate the role of local influences in heritage outcomes and interpretations [32,33].Thus, while power imbalances are clearly evident in the world heritage arena, a wide range of stakeholders potentially shape the development, interpretation, and inscription of cultural and natural sites [34].Although the cultural and natural heritage experts who assess the value of nominated world heritage sites are among these stakeholders, they are rarely the subjects of scholarly analysis [5] despite theoretical reasons for doing so.
World society theory, an institutional approach to global analysis in sociology [16], emphasizes the influence that a variety of actors exert at different levels (e.g., local, national, supranational, and global) in generating and reproducing global structures and processes.The notion of a world polity is invoked to describe a highly diffuse authority structure, without geographical boundaries or an administrative center, which has become increasingly authoritative relative to nation-states in propagating rules and setting standards of behavior in many spheres of social life [35].While a wide range of actors (e.g., intergovernmental organizations, nation-states, universities, corporations, voluntary associations, individuals) can exercise legal sovereignty in the world polity, non-governmental organizations (NGOs) have become especially influential since the 19th century [36,37], shaping a wide range of transnational movements including those promoting world heritage [2], environmentalism [38][39][40], and sustainable tourism [41].
The recently articulated "cultural wealth" perspective in global sociology, which draws heavily on the work of Pierre Bourdieu, focuses on the role of reputational attributes and cultural products in establishing the global status and prestige of a nation [17].Just as individuals use their "cultural capital" (i.e., cultural knowledge, tastes, styles of interaction), in Pierre Bourdieu's [42] formulation, to establish and reproduce their social position, nations draw on their cultural wealth to maintain their status in the global arena.Furthermore, cultural wealth can be converted into economic and political advantage by making a country more attractive to foreign investors or tourists, a process that reproduces global inequalities between states.While international prizes received by its citizens or artworks exhibited in prestigious museums are indicators of cultural wealth, many scholars taking this approach have focused on the quantity and quality of a nation's natural and cultural heritage sites as a source of "symbolic value" [43][44][45][46][47]. From this perspective, states engage in "international impression management" [48] to convey their status to a world audience.Yet Bourdieu's theory also points to the key role of cultural intermediaries in legitimating the reputations of high status actors in fields of cultural production [49].In Bourdieu's terms, INGOs like ICOMOS and IUCN act as "consecrating agents" who verify the cultural and natural heritage sites that exemplify outstanding universal value.
Therefore, we focus our analysis on the evaluations produced by ICOMOS and IUCN due to their influence in setting standards for tourism and sustainability at inscribed sites as well as their role in certifying their universal value.From a world society perspective, the evaluations can provide insights into the extent and timing of the emergence, growth, and institutionalization of concerns about tourism and sustainability in the assessment of world heritage sites as well as how such concerns have changed over time.From a cultural wealth perspective, the evaluations are relevant to understanding how well different states are able to convey the value of their heritage and their competency in managing tourism in a sustainable manner through their nomination dossiers.A state's ability to give the right "impression" to ICOMOS or IUCN is not only important for getting a proposed heritage site inscribed but also indicates how well they will be able to convert their cultural wealth into economic and other forms of advantage.Taken together, our analysis highlights the institutionalization of tourism and sustainability concerns as well as disparities in the perception of touristic threats in the evaluations of heritage sites.Our findings also have practical implications with respect to the role of the advisory bodies in providing specific recommendations that promote the sustainable development and management of heritage tourism.

Materials: Advisory Body Evaluations of Nominated Sites
Evaluations of nominated sites are a central component in the inscription process (see Figure 1).In order to nominate a property for inclusion on the World Heritage List, a country must first sign the World Heritage Convention.Next, the State Party compiles an inventory of its most prized natural and cultural heritage sites, called a Tentative List [50], which represents possible submissions for inscription in the next five to ten years.After creating a Tentative List, a State Party may submit a nomination file for a particular site.Today, nomination files are extensive; they typically include a geographical identification of the site with coordinates and detailed maps, information about its history and development, statements of integrity and authenticity, a comparative analysis with similar properties that have achieved inscription, specific details about conservation and management efforts (e.g., legislative and other regulatory measures, concrete indicators to measure success), and so on.The required contents of the nomination dossiers, which have significantly expanded in complexity over time [2,4,9], are outlined in the Operational Guidelines for the Implementation of the World Heritage Convention [51].Then, each nominated property receives an independent inspection by either ICOMOS, in the case of cultural sites, or IUCN, in the case of natural sites.The results of this inspection are documented in an official "advisory body evaluation" that includes particular details about the site and expert comments on its eligibility for inclusion on the World Heritage List.The evaluations contain recommendations to the State Party and to the World Heritage Committee, which makes the final decisions with regard to inscription.provide insights into the extent and timing of the emergence, growth, and institutionalization of concerns about tourism and sustainability in the assessment of world heritage sites as well as how such concerns have changed over time.From a cultural wealth perspective, the evaluations are relevant to understanding how well different states are able to convey the value of their heritage and their competency in managing tourism in a sustainable manner through their nomination dossiers.A state's ability to give the right "impression" to ICOMOS or IUCN is not only important for getting a proposed heritage site inscribed but also indicates how well they will be able to convert their cultural wealth into economic and other forms of advantage.Taken together, our analysis highlights the institutionalization of tourism and sustainability concerns as well as disparities in the perception of touristic threats in the evaluations of heritage sites.Our findings also have practical implications with respect to the role of the advisory bodies in providing specific recommendations that promote the sustainable development and management of heritage tourism.

Materials: Advisory Body Evaluations of Nominated Sites
Evaluations of nominated sites are a central component in the inscription process (see Figure 1).In order to nominate a property for inclusion on the World Heritage List, a country must first sign the World Heritage Convention.Next, the State Party compiles an inventory of its most prized natural and cultural heritage sites, called a Tentative List [50], which represents possible submissions for inscription in the next five to ten years.After creating a Tentative List, a State Party may submit a nomination file for a particular site.Today, nomination files are extensive; they typically include a geographical identification of the site with coordinates and detailed maps, information about its history and development, statements of integrity and authenticity, a comparative analysis with similar properties that have achieved inscription, specific details about conservation and management efforts (e.g., legislative and other regulatory measures, concrete indicators to measure success), and so on.The required contents of the nomination dossiers, which have significantly expanded in complexity over time [2,4,9], are outlined in the Operational Guidelines for the Implementation of the World Heritage Convention [51].Then, each nominated property receives an independent inspection by either ICOMOS, in the case of cultural sites, or IUCN, in the case of natural sites.The results of this inspection are documented in an official "advisory body evaluation" that includes particular details about the site and expert comments on its eligibility for inclusion on the World Heritage List.The evaluations contain recommendations to the State Party and to the World Heritage Committee, which makes the final decisions with regard to inscription.Both ICOMOS and IUCN have played a prominent role in the development of the world heritage movement [2] (ICOMOS emerged out of the Second Congress of Architects and Specialists of Historic Buildings in 1964 and operates in a variety of capacities to develop and disseminate knowledge about preservation standards and techniques.Today, ICOMOS comprises a global network of experts from a variety of specializations (e.g., architecture, history, archaeology, geography, anthropology, engineering, town planning, etc.), who work to promote "the application of theory, methodology, and scientific techniques to the conservation of architectural and archaeological heritage" [52].IUCN was founded in 1948 to promote international cooperation in natural conservation efforts.Early on, its role included drafting the first UN List of Parks and Equivalent Reserves in 1959 as well as a 1968 proposal to combine the conservation of cultural and natural sites [53].).As permanent advisory bodies, ICOMOS and IUCN play a central role in the process of evaluating sites and, despite some recent controversies, the World Heritage Committee has historically followed their recommendations with regard to inscription fairly closely [54,55].Our data includes every evaluation written by ICOMOS and IUCN for inscribed cultural and natural sites from 1980 to 2010 (N = 811), all of which were retrieved from UNESCO's World Heritage Centre website [56].In order to enhance our comparison of sites that are either distinctly cultural or distinctly natural, we exclude the few mixed sites (N = 25) that were inscribed during this time period.Mixed sites contain both cultural and natural features and are typically evaluated by both ICOMOS and IUCN.Table 1 provides a year-by-year breakdown of the evaluations in our sample by site type.

Methods: Analysis of Advisory Body Evaluations
To prepare the evaluations for analysis after they were downloaded as pdf files, they were processed using optical character recognition (OCR) software and converted back to pdf files.Finally, the evaluations were imported into MAXQDA, a text-based data analysis software that facilitates both quantitative and qualitative content analysis.First, we employed the MAXDictio add-on to the software program to construct a dictionary of key terms and to conduct word counts of the evaluations.In addition to producing total word counts of each evaluation, we used this function to identify all evaluations that contained some direct mention of tourism (including tourism, tourist, and other variants) or of sustainability (including sustainable, unsustainable, sustainably, and other variants.).A strength of this approach is that it enables us to broadly identify when discussions of tourism and sustainability emerged in cultural and natural site evaluations as well as the general extent to which it has become a routine feature of the evaluations over time.However, it is limited in the sense that it does not tell us exactly what was discussed, regarding tourism and sustainability, and how these discussions change over time.
Therefore, we next conducted a detailed qualitative content analysis of a subset of the evaluations that discussed tourism.To give us a sense of how such concerns have changed over time, we focused on all the evaluations from the 1980s (n = 44) and all evaluations from 2006 to 2010 (n = 90) that discussed tourism.Our coding focused on determining for each evaluation: whether or not ICOMOS or IUCN identified tourism as a threat to the site; whether ICOMOS or IUCN expressed positive sentiments about tourism (e.g., expressed optimism about the potential for tourist development, praised the state party for sustainable management of tourism, etc.); and whether ICOMOS or IUCN made specific recommendations with regard to sustainable tourism.Finally, we used this information to identify trends over time as well as to make comparisons across site type (cultural vs. natural) and region.

Results
Below, we first present results of the word count analysis to demonstrate the timing and extent of discussions of tourism and sustainability in the advisory body evaluations produced by ICOMOS and IUCN.Then we provide additional details based on our qualitative coding of the evaluations that contain mentions of tourism.

Word Count Results
First, we provide some contextual information about changes in the advisory body evaluations, based on previous research [4].Overall, the evaluations of cultural and natural sites grow considerably longer over time.Initially, evaluations are only a few hundred words in length but steadily expand over time to several thousand words.Although natural site evaluations are somewhat longer through the 1980s and early 1990s, cultural site evaluations catch and then surpass natural site evaluations in length in recent years (i.e., over 8000 words for cultural sites, on average; over 6000 words for natural sites, on average).This general expansion of the evaluations indicates that they have come to include a much wider range of information and topics of concern over time.
Figure 2 presents the percent of cultural and natural site evaluations that contain direct discussion of tourism over time.Initially, there is a noticeable gap between natural and cultural site evaluations as ICOMOS rarely raised tourism concerns, while IUCN discussed tourism in most evaluations by 1983 and continued to do so thereafter.Particularly during the 1990s, however, cultural and natural site evaluations converged.By 2006, over 80% of cultural site evaluations and 100% of natural evaluations discuss tourism and nearly all evaluations do the same thereafter, which indicates that tourism-related issues have become firmly institutionalized in the assessment of world heritage.By contrast, discussion of sustainability is much slower to emerge, particularly in cultural site evaluations (see Figure 3).After 1999, it begins to appear more often and gradually approaches the proportion of natural site evaluations that directly address sustainability.At the end of the time period we study, about half of all evaluations produced by both ICOMOS and IUCN contain some discussion of sustainability.
Sustainability 2016, 8, 261 5 of 14 used this information to identify trends over time as well as to make comparisons across site type (cultural vs. natural) and region.

Results
Below, we first present results of the word count analysis to demonstrate the timing and extent of discussions of tourism and sustainability in the advisory body evaluations produced by ICOMOS and IUCN.Then we provide additional details based on our qualitative coding of the evaluations that contain mentions of tourism.

Word Count Results
First, we provide some contextual information about changes in the advisory body evaluations, based on previous research [4].Overall, the evaluations of cultural and natural sites grow considerably longer over time.Initially, evaluations are only a few hundred words in length but steadily expand over time to several thousand words.Although natural site evaluations are somewhat longer through the 1980s and early 1990s, cultural site evaluations catch and then surpass natural site evaluations in length in recent years (i.e., over 8000 words for cultural sites, on average; over 6000 words for natural sites, on average).This general expansion of the evaluations indicates that they have come to include a much wider range of information and topics of concern over time.
Figure 2 presents the percent of cultural and natural site evaluations that contain direct discussion of tourism over time.Initially, there is a noticeable gap between natural and cultural site evaluations as ICOMOS rarely raised tourism concerns, while IUCN discussed tourism in most evaluations by 1983 and continued to do so thereafter.Particularly during the 1990s, however, cultural and natural site evaluations converged.By 2006, over 80% of cultural site evaluations and 100% of natural evaluations discuss tourism and nearly all evaluations do the same thereafter, which indicates that tourism-related issues have become firmly institutionalized in the assessment of world heritage.By contrast, discussion of sustainability is much slower to emerge, particularly in cultural site evaluations (see Figure 3).After 1999, it begins to appear more often and gradually approaches the proportion of natural site evaluations that directly address sustainability.At the end of the time period we study, about half of all evaluations produced by both ICOMOS and IUCN contain some discussion of sustainability.Based on the word count patterns, it is clear that sustainability is not typically associated with discussions of tourism until recent years, particularly in the evaluations of cultural sites.Across all evaluation types, the vast majority (79.4%) of instances in which the two concepts are linked occur after 2000, despite the fact that sustainable tourism had already been the subject of considerable international organizing since the late 1980s and early 1990s [41].In total, 102 of the 811 evaluations (12.6%) discuss both sustainability and tourism together.Although the term "sustainable tourism" Based on the word count patterns, it is clear that sustainability is not typically associated with discussions of tourism until recent years, particularly in the evaluations of cultural sites.Across all evaluation types, the vast majority (79.4%) of instances in which the two concepts are linked occur after 2000, despite the fact that sustainable tourism had already been the subject of considerable international organizing since the late 1980s and early 1990s [41].In total, 102 of the 811 evaluations (12.6%) discuss both sustainability and tourism together.Although the term "sustainable tourism" itself is relatively rare, mentions of sustainable development or sustainable management are sometimes linked to tourism-related concerns.Nearly one in four natural site evaluations (23.9%) contain terms related to both sustainability and tourism, but only about one in ten cultural site evaluations do the same (9.7%).If we focus on the latest five years of our study (2006)(2007)(2008)(2009)(2010), 11 out of 20 (55.0%) natural and 29 out of 70 (41.4%)cultural evaluations include both tourism and sustainability, which indicates that it is becoming fairly common by the end of our study period.To some extent, mentions of tourism and sustainability may reflect changes in the Operational Guidelines [51] that outline the issues States Parties must address in their nomination dossiers.Therefore, we turn to our qualitative coding results to focus on changes in the ways that the advisory bodies assess the threats and opportunities associated with tourism and sustainability as well as the relevant recommendations they provide.

Qualitative Coding Results
The results of the qualitative coding provide additional insights into the patterns described above.Although the discourse of sustainability is rarely invoked in the 1980s evaluations, discussion of tourism gradually increases for cultural sites during this decade and becomes the norm for natural sites.Yet even when tourism is discussed, it is typically fairly brief and often more descriptive than evaluative.For instance, the ICOMOS evaluation of India's Group of Monuments at Hampi simply mentions one monument as being a "favorite of tourists today" and refers to a plan for developing "touristic and scientific infrastructure" [57] (p.2).Likewise, IUCN writes that the waterfalls in Iguazu National Park are "one of the principal tourist attractions in Argentina" and notes that there are plans for additional tourist facilities, but does not describe this as a concern [58] (p.2).Even for some sites that attract a large number of visitors, tourism is not described as a threat.For example, "touristic development" is described by ICOMOS as an integral part of urban Rhodes in Greece, "desirable or not" [59] (p.3); and any concerns about the 680,000 yearly visitors to the Great Smoky Mountains in the USA are downplayed by the IUCN evaluation, which notes that the tourist infrastructure has mostly been developed outside the Park and it provides economic benefit to people in the surrounding area [60].In some cases, brief advice is provided by the advisory body, whether or not a specific threat is identified, such as when ICOMOS recommended that no "tourist facilities" be constructed within view of the Temple of Apollo Epicurius at Bassae in Greece [61] (p.3).As in the examples offered here, most evaluations in the 1980s are fairly equivocal and do not explicitly refer to tourism as a threat to heritage.
In total, only 11 of the 44 cultural and natural evaluations (25.0%) characterize tourism as a threat, either currently or potentially, to the site under review.A few instances elicit strong concern from the advisory bodies, such as ICOMOS' recommendation, with regard to the Great Zimbabwe National Monument, to postpone "installation of tourist facilities which are expensive and dangerous" until the archaeological areas are properly excavated [62] (p.3).Similarly, a review of the Chan Chan Archaeological Zone in Peru leads ICOMOS to question the restoration and development projects underway, which it sees as efforts "to satisfy the demands of mass tourism" [63] (p.3).Among the examples from natural site evaluations, IUCN describes Tanzania's Kilimanjaro National Park as threatened by high "tourism intensity", which results in litter and challenges of facility maintenance [64] (p.3).Yet most of the sites for which tourism is seen as a threat include somewhat vague and usually succinct statements.Paphos in Cyprus, for instance, is simply said to be threatened by "commercial (touristic) developments" [65] (p. 2), while tourism is described as a "disturbance" in Nepal's Royal Chitwan National Park, ranking just behind the threats from fire and grass-cutting by locals [66] (p.2).
By comparison, nearly as many cultural and natural evaluations in the 1980s-10 out of 44 (22.7%)-describe tourism as having a positive relationship with the site, either as an indicator if its outstanding universal value, a boon to the local economy, or due to exemplary management.Ksar of Ait-Ben-Haddou in Morocco, for instance, is said to possess every indication that it belongs on the World Heritage List "because of the celebrity it enjoys among tourists" [67] (p.2).Likewise, the development of a new "tourist complex" at Tipasa is credited with bringing "new life to the ruins", although ICOMOS recommends that the Algerian government place strict controls on any future tourist facilities [68] (pp.2-3).The Historic Center of Evora in Portugal is described as one of the major tourist attractions in the region, but ICOMOS emphasizes that the "museum city has retained all of its traditional charm" [69] (p. 1).Among natural sites, IUCN welcomes efforts to promote tourism in Cote d'Ivoire's Comoe National Park and even suggests expanding the Park's boundaries to enhance the "ecological and touristic value of the property" [70] (p.2).Plans to develop the park infrastructure and partner with the private sector tourism industry in Canada's Gros Morne National Park are encouraged by IUCN because they will "diversify and increase employment opportunities for local communities" [71] (p.3).In short, when evaluations in the 1980s made mention of tourism it was typically brief, ambiguous in its assessment, and rarely made specific recommendations.Table 2 summarizes the coding results and also reports them by region.
The regional breakdown of the coding results indicates that Latin American/Caribbean (LAC) sites as well as the European/North American sites (EUR) have a higher than average proportion of evaluations that describe tourism as a threat.Yet EUR sites, along with African (AFR) sites, also have a higher than average proportion of ambiguous evaluations in which tourism is not identified as a specific threat.AFR sites have a high proportion of positive comments about tourism, several of which involve praise from IUCN for having well-managed national parks.Arab states (ARB) also receive positive assessments about tourism in 2 out of its 3 inscribed sites during the 1980s, while sites in Asia/Pacific Islands (APA) and LAC regions contain no positive comments about tourism.Across all regions, a similar proportion of sites receive specific recommendations from the advisory bodies ranging between 20.0% for EUR and LAC sites to 33.3% for ARB sites.Whereas tourism is discussed to a limited extent and often in ambiguous ways in the 1980s, concerns about tourism become a more consistent aspect of advisory body evaluations over time, especially after the issue of sustainable tourism became an institutionalized principle of world heritage discourse.Just as the evaluations expand in length and complexity over time, so do the assessments of tourism-related issues.In our qualitative analysis of cultural and natural site evaluations written from 2006 to 2010 (N = 90), we continued to code for direct mentions of tourism as a threat; positive sentiments about tourism or its management at the site; and descriptive or ambiguous comments about tourism that do not provide a negative or positive assessment of tourism.Yet due to the increased amount and complexity of comments about tourism, some combination of these views could appear in the same site evaluation.So, for a few sites, the evaluations may identify tourism as a threat but also include a positive assessment of tourism development plans or management.Also, we coded instances in which ICOMOS or IUCN make specific recommendations with regard to the development, management, interpretation, or other aspects of tourist activity at a site.
Similar to the site evaluations written in the 1980s, most evaluations (63.3%) do not identify tourism as a threat or are at least equivocal about its relationship to the site from 2006 to 2010.During most of this time period, "tourism pressures" is an institutionalized subheading in ICOMOS evaluations under the broader heading "factors affecting the property", but many evaluations explicitly state that tourism is not much of a concern in this section.What is much different during this time period, however, is that ICOMOS and IUCN are much more likely to make specific recommendations-57.8% of the time, compared to 22.7% of the time in the 1980s-even when tourism is not described as a significant threat to the site currently.In such cases, the appropriate advisory body often recommended a formalized management plan or strategy to prepare for the possibility of increased tourism, even though it was not apparent at the time.Following world society theory, we think such examples highlight the fact that concerns over tourism are not merely a functionalist response to "actual" increasing threats, but are often the ritual expression of concerns that have widely diffused and become formally institutionalized in official documents and decrees [16].
Another difference, relative to the 1980s, is that formal recommendations, many of which focus on future tourism plans, are most common in the evaluation of sites from less developed countries during 2006 to 2010.As shown in Table 3, evaluations of sites in African (66.7%),Asian (74.2%), and Arab (83.3%) states are much more likely to contain such recommendations compared to sites in European/North American (42.4%) and Latin American (36.4%) states during this period.For example, in their evaluation of the Bisotun archaeological site in Iran, ICOMOS made no mention of tourism as a threat but recommended that the issues of visitor reception and the presentation of the site needed to improve in the future.What is more, they requested than any future plans regarding these issues receive the prior approval of the World Heritage Committee: "ICOMOS requests the State Party to report to the World Heritage Committee on the design and construction of access routes to the site and the development and design of eventual visitor facilities, before such works are undertaken" [72] (p.74).Given that no specific threats were identified in the evaluation, this seems to be a fairly heavy-handed recommendation.Likewise, in its 2007 evaluation of the Red Fort Complex in India, ICOMOS expressed concern about the lack of a visitor management strategy to distribute tourists and recommended that an "integrated approach to research, conservation, monitoring, tourism, education and local social values" be included in their Comprehensive Conservation Management Plan [73] (p.103).In its 2008 evaluation of the Socotra Archipelago in Yemen, IUCN noted that Socotra was an isolated site with few tourists.Nonetheless, they recommended very specific objectives to be included in an Ecotourism Master Plan that: And in Iran, once again, the 2010 evaluation of the Tabriz Historic Bazaar Complex by ICOMOS found that there was "no pressure from tourism" yet it was recommended that training programs on sustainable tourism be developed for owners and managers to make sure they were prepared to tackle tourism issues [75] (p.138).
At the same time, site evaluations more often described tourism as a current or imminent threat from 2006 to 2010 (37.8% of the time) compared to the 1980s (25.0% of the time).Even more striking is the increasing variety of forms such threats took, according to ICOMOS and IUCN.Again, sites in less developed countries were more likely to be seen as threatened by tourism with the highest rates evident in Asian (54.8%) and African (44.4%) sites during this period.Not surprisingly, extensive human contact via tourism could be a threat when it degraded material structures or natural environments.For example, in its 2009 evaluation of The Sulaiman-Too Sacred Mountain in Kyrgyzstan, ICOMOS highlighted the persistence of vandalism and negligence, writing: "Uncontrolled visitor access for many years resulted in a damage to petroglyphs found in the lower parts of the first and second peaks: a number of modern graffiti, mainly painted, but also those engraved and/or pecked, cover many rock surfaces" [76] (p.25).
Similarly, the construction of tourist accommodations could be viewed as excessive and indiscriminate when it degraded the site itself.For example, in its 2008 evaluation of the Sacred Mijikenda Kaya Forests in Kenya, ICOMOS recommended that one of the forests (Kaya Kinondo) be removed from the nomination altogether due to "severe threats" from tourism development, which had replaced forest land with visitor accommodations and threatened traditional ways of life [77] (p.4).In this case, as in others, eco-tourism or sustainable tourism efforts were a common solution.In the evaluation of the Monarch Butterfly Biosphere Reserve in Mexico in 2008, IUCN found that tourist accommodations did not degrade the site or directly harm the butterfly colonies but, rather, were unsightly.They write: "Current tourism impacts relate not so much to the butterfly colonies, but rather to the area's natural beauty.Most of the existing tourism infrastructure has been developed by local communities without considering visual or environmental impacts, and this detracts in a major way from the visual integrity of the sites that are visited by tourists" [78] (p.97).
In some cases, the threat of tourism extended to traditional ways of life that are integrated into the physical environment of the site.For example, in its 2008 evaluation of the Fujian Tulou-a group of large, communal clan houses in China-ICOMOS identified imminent threats from tourism that could degrade the site and the surrounding environment, which could then affect the lifestyle of its inhabitants."It is recognized . . .that too many visitors may adversely impact the structures, especially the wooden floors, which will affect the traditional way of life and culture.The creation of tourist facilities will, furthermore, have a negative impact on the environment" [79] (p.26).Adding to this, ICOMOS argued that the physical presence of tourists themselves could diminish the authenticity of the site."The tulou exist in a fragile environment that will come under additional pressure with the expected growth in tourism.Part of their value lies in their relationship with agricultural activities carried out in the surrounding landscape.If all the tulou became museums there could be a significant loss in authenticity" [79] (p.26).Thus, while tourist pressures tend to threaten material structures or environmental landscapes, in this case the very act of visitors being present (and observing) threatens the traditional behavior of those who still inhabit these structures, which is part-and-parcel of their outstanding universal value.Overall, the threats of tourism appear more often in cultural and natural site evaluations in later years and they are described in much greater detail and variety compared to earlier evaluations.
Given the increased identification of tourism threats, it is not surprising that fewer site evaluations express positive sentiments with regard to the relationship between tourism and heritage sites between 2006 and 2010.During the 1980s, nearly one in four site evaluations (22.7%) expressed some positive aspect of tourism whereas only about one in seven (14.4%) do the same in the later time period.With the exception of three positive mentions in Asian site evaluations (i.e., 9.7% of the time), all positive expressions appear in sites from the EUR (21.2%) and LAC (27.2%) regions.As a positive attribute, tourism was viewed as something that could add value to a potential world heritage site, particularly if it was already well managed by the nominating State Party.For example, in its 2006 evaluation of the Old Town of Regensburg in Germany, ICOMOS noted that the site was well managed and "the city is well prepared for tourism" [80] (p.104).In the same year, ICOMOS' evaluation of Le Strade Nuove in Genoa noted that the city had much improved its capacity to manage tourism and gave no specific recommendations about tourism development [81].ICOMOS' evaluation of the Jeju Volcanic Island and Lava Tubes in South Korea in 2007 acknowledged a high number of tourists to the site but considered it well managed and not beyond its "carrying capacity" and also applauded the site as an exemplar of the involvement of civil society in world heritage due to the high level of public awareness in Jeju Province about the site, its value, and potential inscription [82] (p.33).Despite 650,000 visitors per year, ICOMOS concluded in 2010 that the Episcopal City of Albi in France was well managed and that pressures were well understood.Nonetheless, they recommended the need for tourist signs and for "tourism monitoring indicators" to be defined and implemented [83] (p.243).Finally, ICOMOS found no issues with tourism at the Seventeenth-Century Canal Ring Area of Amsterdam in its 2010 evaluation, despite nearly 5 million hotel nights by tourists in 2007, because facilities were adequate and growing.Tourism was also seen as an important part of the economic growth of this city [84].

Discussion
Taken together, the results of our analysis of the advisory body evaluations offer a number of insights, both practical and theoretical.As we argued in the introduction, ICOMOS and IUCN are influential stakeholders in the world heritage arena, although different theoretical perspectives conceptualize their roles in somewhat divergent ways.In our view, foregrounding the part that these advisory organizations play in assessing and articulating the relationship between tourism and the value of world heritage sites complements and contributes to the extant scholarship on this topic.Among other things, it demonstrates that tourism-related issues have joined a panoply of concerns that heritage experts must take into account when appraising the universal value of a cultural or natural property.Yet given the growing variety of sites nominated for inscription and the increasing complexity of the evaluations, it is small wonder that discussion of and recommendations regarding sustainable tourism remain fairly ambiguous in this early stage of institutionalization.
Indeed, some have noted the uneasy relationship between sustainable tourism and development, suggesting that UNESCO appears to simultaneously embrace it with one hand and shun it as a threat to heritage with the other [9,12].Some of our findings certainly resonate with the uncertainty and ambiguity with which ICOMOS and IUCN address tourism in their site evaluations.In attempting to transform abstract concepts (e.g., outstanding universal value, sustainable tourism) into concrete practice, it is not entirely surprising that straightforward recommendations and uniform interpretations are hard to come by.Others have argued that heritage professionals were highly antagonistic to tourism in decades past but have become more favorable to the tourism industry in recent years [5].Our analysis suggests that this generalization may not extend to the experts that evaluate sites for World Heritage List inscription, as they appear to have become more concerned about the threats of tourism and less likely to highlight its positive aspects by the end of our study period.Given that site evaluations in less-developed countries are more likely to include formal recommendations regarding tourism plans, evaluators should be particularly sensitive to the balance between development and sustainable tourism in these countries, which may rely heavily on tourist revenues yet lack some of the bureaucratic and technical capacity required to ensure robust management plans.
On a practical level, these findings highlight the ongoing challenges of clarifying what constitutes sustainable tourism and how it can be applied to cultural and natural properties of such remarkable diversity.Gullino, Beccaro and Larcher [85] similarly note a lack of specific models, rules or definitions associated with UNESCO's call for sustainable management plans and they demonstrate the challenges this presents, specifically for rural world heritage sites.The difficulty of providing clear recommendations to States Parties may also contribute to some of the frustrations that have led to pointed criticism of the advisory bodies by delegates to the World Heritage Committee in recent years [55].Next, we highlight the relevance of our findings to two approaches to global analysis in sociology, world society theory and the cultural wealth perspective.

World Society Theory
The expansion of discourse about sustainable tourism in the site evaluations follows a pattern that has been frequently documented by world society scholars in other domains of global activity.As ideas about human rights [86], corporate social responsibility [87], or government transparency [88], for example, become widely diffused taken for granted, they are increasingly applied and enacted in various institutional settings around the world.Similarly, as sustainable tourism becomes a culturally legitimate principle in world society, it becomes a routinized feature of cultural and natural site evaluations.This is especially evident from the fact that specific recommendations-for example, to create a formal plan for the sustainable development and management of tourism-become commonplace even for sites that receive few tourists or where tourism is not perceived as a threat to their integrity.Consistent with world society theory, specialized INGOs like ICOMOS and IUCN exert considerable authority in defining and propagating standards of sustainable tourism in the world heritage arena, based on their scientific and technical expertise.Future research from this perspective could also explore the global emergence and diffusion of tourism-and sustainability-related concerns outside the world heritage arena (e.g., in the United Nations, at world conferences, and among other prominent INGOs) and how this may have affected the timing of their expansion in the recent advisory body evaluations of ICOMOS and IUCN.

Cultural Wealth of Nations
At the same time, our findings resonate with aspects of the recent cultural wealth perspective in global sociology and are suggestive of ways to develop it further [17].As described in the introduction, this approach focuses on the ways that nations draw on their stocks of cultural capital to enhance their status and reproduce other forms of advantage (e.g., economic, political).Countries that are endowed with cultural wealth are better able to manage the impressions that others in the world system hold of them and countries can engage in impression management to emulate the cultural styles of high-status nations [48].Thus, a state may attempt to "upgrade" from mass tourism to heritage tourism in order to enhance its symbolic status, which in turn will generate economic benefits [47].
From this perspective, our findings with regard to regional variation in the perceptions of touristic threats or commendations for model tourism management can be explained by the fact that countries have unequal capacities to exploit their cultural wealth for status advantages.As inscription on the World Heritage List becomes an increasingly salient indicator of a country's cultural wealth, we see clear advantages emerge for European and North American states (i.e., they are more often commended for sustainable management of tourism and their sites are less likely to be seen as threatened by tourism).Ultimately, this enhances the symbolic value of their inscribed sites, thereby reproducing their advantages in the world system.Our approach, which focuses on the assessments of value made by influential intermediaries (i.e., experts at ICOMOS and IUCN), highlights a useful addition to the perspective.To date, cultural wealth scholars have focused primarily on "impression management" undertaken by states to advance their symbolic status but have given little direct attention to how these claims are received by their intended audiences.In this paper, we focus on how claims to symbolic value are evaluated by advisory bodies that act as "gatekeepers" to cultural wealth.Future work in the cultural wealth perspective could draw on sociological scholarship on valuation and evaluation to better understand how claims to cultural wealth are legitimated by various audiences [89].In the case of world heritage, ICOMOS and IUCN play a central role in articulating and institutionalizing concerns about sustainability and tourism as well as assessing whether such concerns add to or detract from the outstanding universal value of cultural and natural sites.

Figure 1 .Figure 1 .
Figure 1.World heritage site nomination process.Both ICOMOS and IUCN have played a prominent role in the development of the world heritage movement [2] (ICOMOS emerged out of the Second Congress of Architects and SpecialistsFigure 1. World heritage site nomination process.

Figure 2 .
Figure 2. Percent of cultural and natural site evaluations that discuss tourism.

Figure 3 .
Figure 3. Percent of cultural and natural site evaluations that discuss sustainability.
(a) maintains the current focus on low key, nature based tourism, based on the appreciation of natural values; (b) includes a carrying capacity assessment to guide tourism development . . .; (c) provides for direct and adequate financial contributions from tourism to . . .conservation and community development . . .; (d) closely involves the Yemeni General Tourism Development Authority and Tourism Promotion Board; (e) considers options for engaging in partnerships with environmentally sensitive private sector; and (f) addresses the lack of trained local tourist guides and literature [74] (p.9).

Table 1 .
Cultural and natural site evaluations analyzed, by year and type.

Table 2 .
Summary of coding results for 1980s site evaluations that discuss tourism.
Abbreviations refer to UNESCO Regions (AFR = African States; APA = Asia and the Pacific; ARB = Arab States; EUR = Europe and North America; LAC = Latin America and the Caribbean).

Table 3 .
Summary of coding results for 2006-2010 site evaluations that discuss tourism.Abbreviations refer to UNESCO Regions (AFR = African States; APA = Asia and the Pacific; ARB = Arab States; EUR = Europe and North America; LAC = Latin America and the Caribbean).