The Nature of Airport Brand Associations

: This study examines the nature of brand associations that air travellers form with airports and which associations are important when choosing between airports. Using semi-structured qualitative interviews, this study collected information about 240 participants’ most recent trips using air travel, encompassing 642 airport visits and 88 airports worldwide. The associations that participants made with the airports they travelled through were collected, as well as the sorts of associations that are important for choosing between airports and why those associations are important. The data were analysed using thematic analysis, revealing 13 themes each for airport brand associations and important associations for choosing between airports and 14 themes for reasons why those associations were important. Single-sample t -tests reveal that each of these themes has a different effect size in terms of its effect on airport brand association formation and its effect on attitudinal brand choice. This study contributes to the air transport and tourism literature by providing a detailed account of which associations air travellers form with airports and which are used for choosing between airports by contextualising these findings by viewing airports as compound brands. Managerial implications are also provided along with avenues for future research.


Introduction
Airports can be defined as providers of "all the infrastructure needed to enable passengers and freight to transfer from surface and air modes of transport and to allow airlines to take off and land" [1], p. 1.While airports usually provide these core services themselves, there are also trends in airport commercialisation and privatisation worldwide that encourage enterprise and efficiency [2,3] and thus diversification into non-aeronautical commercial activities [4,5].Accordingly, airports have become facilities that tend to have tenants that assist in providing services for air passengers by providing food and beverages, retail, duty free shops, car rentals, and other special services [6,7].In turn, airports facilitate value creation for their tenants by providing facilities that allow access to the airport's clientele [8].Airlines provide passenger traffic to airports but also rely on airport support to be able to implement strategies such as point-to-point and hub-and-spoke networks [9,10].Henderson et al. [11] identify that these peculiarities of airports result in the multi-creation of brand associations sourced from different entities to form a compound brand (which they also observed applied to shopping malls).Their study provides evidence that airport brands are compound brands by analysing airport associations and important associations for choosing between airports in terms of which entity is the source of such associations (and an equivalent study for shopping malls).This study builds upon their work by using a subset of the same dataset (only the participants for their airport study, not the shopping mall study) to examine the sorts of associations passengers make with airports they travel through (hereafter called 'associations'), which ones are perceived to be important for choosing between airports for future trips (hereafter called 'important associations'), and the reasons for important associations (these reasons were not provided in Henderson et al. [11] due to the authors' different focus).This study examines these thematically and investigates all themes for associations, important associations, and reasons for important associations as potentially having multiple entities as sources.Accordingly, this study aims to contextualise airport brand management within the framework of compound brands.This information will provide practical contributions for airport managers and policymakers to help them prioritise areas of focus within the context of a compound brand (i.e., where some important areas may only allow for diffuse control).Specifically, this study aims to answer the following research questions: 1.
What sorts of associations do air travellers recall with an airport brand name from a recent trip? 2.
What sorts of associations are perceived to be important in determining airport brand choice?3.
Why are some associations more important than others in determining airport brand choice?
This study begins by reviewing brands and branding, branding in the context of airports, and the idea of airports as compound brands.The research method and results are presented and discussed, followed by a series of managerial implications and avenues for future research.Collectively, this study provides a holistic overview of the nature of brand associations that air travellers make with airports, which ones matter, and why.Importantly, it also begins the application of the compound brand concept to airports by contextualising the concept's importance for the creation and management of airport brand associations.Past research on airport branding has been framed from the perspective of conventional branding and has not sufficiently addressed the peculiarities of the multi-creation of brand associations from different entities at airports.This study applies a different approach to airport branding, providing clear and practical managerial implications within the framework of compound brands.

Literature Review 2.1. Brand Associations
According to Aaker [12], p. 109, brand associations can be thought of as "anything linked in memory to a brand".Brand associations are studied for a number of reasons, including their effect upon consumer behaviour [13] and their contribution to brand equity [14], and because more behaviourally loyal customers tend to have more brand associations [15].Keller [16], p. 10, highlights that marketing programmes are aimed at establishing "favourable, strong, and unique brand associations in memory so that consumers purchase the product or service", conceptualising how certain brand associations lead to customer-based brand equity.van Osselaer and Janiszewski [17] identify two ways in which consumers form brand associations: (1) through human associative memory (HAM), where feature-benefit associations of brands develop independently; and (2) through adaptive learning, where different features of a brand compete in memory to predict benefits, and feature-benefit associations form interdependently.The likelihood of a consumer using either one is influenced by their level of motivation to learn to predict benefits from associations, where higher motivational significance increases the likelihood of adaptive learning, and lower motivational significance increases the likelihood of HAM learning.In terms of recalling brand associations, brand usage is very important in influencing a consumer's propensity to give brand associations [18,19]; hence, unprompted brand association recall will adversely affect the number of associations for nonusers of a brand [20].This consideration has influenced the method of this study, which uses the unprompted recall of brand associations for airports that a participant travelled through on their last trip (i.e., only examines brand user's associations, not those of brand nonusers).

Airport Branding
One key area of research within airport branding has been examining the influence of an airport's brand upon different aspects of performance.Marcucci and Gatta [21] treat customer loyalty and branding as synonymous by using a 'brand coefficient' defined in terms of customer loyalty for explaining heterogeneity in airport preference.Lee and Park [22] find that sustainable airport brands have a strong and positive mediating effect on airport business performance.Chung et al. [23] instead focus on the financial value of an airport brand by valuing the brand equity of Incheon International Airport using financial techniques.They suggest several ways of increasing the financial value of the airport's brand as an intangible asset.
Instead of examining business performance in relation to branding, Halpern and Regmi [24] examine 1562 airport brands worldwide in terms of their names and their slogans to see if there are differences internationally.They find that approximately threequarters of all airports are named after the place that they are located (and/or the nearest main city or town), for example, Hong Kong International Airport or Beijing International Airport.They also find that only one-tenth of airports have a slogan (e.g., "LAX is happening" for Los Angeles International Airport or "Hello World" for Birmingham Airport), with North American and privatised airports being more likely to have one.Accordingly, their study provides evidence that brand names and slogans are a greater consideration for airports that are operated by private companies rather than those that are publicly owned.In a study on marketing innovations at European airports, Halpern [25] shows that airport managers tend to focus more attention on targeting specific airlines, modifying facilities, and developing strategic marketing partnerships rather than on aspects such as promoting a recognised brand.
Kefallonitis and Kalligiannis [26], p. 523, find that airport branding helps to create "a sense of place" and "unification of like-minded passengers based upon their choice of airport or members of a like-minded group (imagined-communities; such as a social media group of aviation geeks)".They also find that the brand of an airport is determined by its service quality, variety of shops, passenger lounges, and other benefits.Airport brands may also incorporate certain "cultural, artistic, architectural and customary characteristics of the local city" (p.523).Kefallonitis and Kalligiannis [26] appear to implicitly acknowledge that airport brands are multifaceted and created by multiple entities, including shops (operated by tenants) and the location where the airport is situated.However, there is also a tacit assumption that airport brands are always positive given that the term 'benefit' is used but no negative terms are used.This is a common issue within the branding literature, with many definitions taking positive and evangelical stances towards the brand [27].Nevertheless, there will likely be negative associations made with airports according to the nature of experiences that air travellers have when travelling through them (e.g., some passengers have issues getting through security checks or have to pay fees for services like parking).
Tse [28] identifies eight elements of airport branding strategies: (1) retail pricing strategies; (2) selection of retail outlets; (3) choice of food and beverage outlets; (4) architectural layout and design; (5) artwork; (6) services and entertainment; (7) service staff; and (8) airport logos, slogans, and wordmarks.Firsty et al. [29] use these eight elements to explore the impact of airport branding strategies on customer experience and find that collectively, these eight elements accounted for 49.5% of customer experiences at Soekarno-Hatta International Airport's Terminal 3.All eight elements had over 75% of their sample of 120 participants agreeing or strongly agreeing that they are important.Importantly, such strategies recognise that airports do have some control over the other stakeholders that help create their brands, for example, by selecting tenants to obtain a variety of shops and restaurants.While Ijevleva and Paramonovs [30] find that no airports within the Baltic States used terms like "branding" within their vision statements, usually, at least some of the eight elements of airport branding strategies were present.Accordingly, while not all airports may explicitly focus on branding, there are usually elements of their strategies that appear to implicitly affect their brands by affecting their underlying brand associations.
Paternoster [31] outlines the difficulty of airport customer service in that air travellers hold airports accountable for the performance of many stakeholders and theorises that airport branding can be improved only by taking a strategic and holistic approach.Similarly, Castro and Lohmann [32] analyse airport vision statements to identify marketing and branding strategies.They find that airports tend to use branding strategies similar to large corporations, despite acknowledging that the way airports develop their brands is complex and involves "a number of stakeholders with potentially different representations of the single corporate brand" (p.4).In this sense, both articles highlight a similar issue regarding airport branding: airport brands are created by multiple stakeholders and are likely to need their own strategies because they are unlikely to fit conventional brand types, such as corporate or product brands.

Airports as Compound Brands
A common theme within the reviewed literature has been that airport branding relies upon many different stakeholders, regardless of what brand concept is being measured.This aligns well with the findings presented by Henderson, Avis, Tsui, Ngo, and Gilbey [11], which suggest that airports are compound brands because their brand associations are multi-created by the focal branded entity (the airport), its tenants (airlines, shops, food and beverage outlets, and others), and ancillary entities (location, government security measures, and transport providers).Their paper was focussed on conceptually delineating compound brands from other types of brands using airports and shopping malls as case studies.Due to this purpose, its analysis for airports was limited to examining which entities acted as the sources of different airport brand associations.A depiction is shown in Figure 1.This study presents a different analysis of the same data based upon managerial themes for associations and also presents the reasons for why some associations are important among air travellers in choosing between airports (and others are not) for their journey based on data collected from the same interviews as used in Henderson, Avis, Tsui, Ngo, and Gilbey [11], though the interviews were not analysed for that purpose in their study.Importantly, this study can commence by acknowledging that airport brand associations are sourced from multiple different entities and that airports have varying levels of control over those entities (e.g., airport management can choose tenants but have little or no control over government-mandated security protocols).This is a critical consideration when interpreting the results of this study and attempting to find managerial implications that are actionable and realistic given the constraints and resources an airport has in managing its own brand.

Airport Brand Choice
Because this study addresses the topic of how air travellers choose between airports (called airport brand choice), it is relevant to briefly discuss airport competition because if air travellers can choose between airports in their journey, then this implies that airports compete with one another.While this may be true, levels of airport competition vary between cities, regions, and countries [33][34][35].For example, in New Zealand and Australia, distance between airports makes airport competition for origin-destination travel negligible [34,36].In other parts of the world, substantial intra-urban (within a city), inter-urban (between cities), or multi-airport region (MAR) competition exists.For example, there are high levels of intra-urban airport competition in the city of London because it has six airports competing with each other: Heathrow, Gatwick, Stansted, Luton, City, and Southend [37,38].Inter-urban competition is particularly prominent between major hub airports (e.g., Hong Kong and Singapore Changi), primarily determined by their geographic position and specialisation towards particular markets [39,40].In light of these differences, the findings as to which airport brand associations are important for determining airport choice might be most relevant to airports that have higher levels of competition.However, the act of finding what is important for air travellers is still a useful exercise for airports with lower levels of competition because it can help their managers prioritise different activities from an air traveller perspective.

Sampling Procedure
An a priori power analysis was conducted using G*Power version 3.1.9.7 [41] to determine the minimum sample size required to test the study hypotheses (i.e., that each theme was statistically significantly different from 0). Results indicated that the required sample size to achieve 80% power (1 − β) for detecting a small effect size (d = 0.2), at a significance criterion of α = 0.05, was 156 for a one-tailed single-sample t-test.Seeking to also provide a useful and pragmatic sample from within the population, the authors decided that a sample size of at least 200 would be sufficient for achieving sufficient statistical power.
Participants were recruited in two cities in the Lower North Island of New Zealand, Palmerston North and Wellington.Both cities have airports with scheduled flights from multiple airlines; however, Palmerston North only has domestic flights on offer, while Wellington has an international airport.This is important for ensuring that we have a good split between airport use for domestic and international flights.In Palmerston North, we interviewed participants in a shopping mall and in the periphery of Te Marae o Hine-The Square in the central city.In Wellington, we interviewed participants down Cuba Street, which is a major thoroughfare and tourist attraction and was chosen to ensure that our sample contained those who had travelled to New Zealand, rather than just New Zealanders.Despite the use of convenience sampling, we considered that the combination of locations for recruiting participants would produce a useful and pragmatic sample with demographic diversity.
Participants needed to be at least 16 years old, to have travelled through an airport before, and not be employed in an airport.The interviews were recorded on a tablet and then later transcribed.This study was deemed to be low-risk and was therefore registered as such on the Massey University Human Ethics Database.

Materials
This study used semi-structured interview questions (see Appendix B) to examine airport brand associations, important airport brand associations, and reasons for important airport brand associations.This instrument was piloted on 15 participants to check for ease of completion.As no issues were identified, these 15 participants comprise part of the final sample of 240 participants.
To provide ecological validity for this study, the semi-structured interview asks about a participant's most recent trip using air travel and identifies the airports that they travelled through on that trip (i.e., departure airport(s), transit airport(s), and arrival airport(s)).In some instances, participants travelled back via a different route on the same trip and so may have multiple departure or arrival airports as a result (e.g., some participants flew into one location, went on a road trip, and flew back from a different location).The name of each airport is then used to ask the participant to recall associations that they have with the airport (if any).This is consistent with the conceptualisation of airport brand associations as anything that comes to mind when presented with the airport brand [12,42], in this case, the airport's name.By probing the participant's most recent trip using air transport, the interview randomises which airports the participants are discussing and also provides an easy conversational basis to discuss airport brands.Because only 21.50% of participants had never visited the airport before, we were more interested in obtaining the totality of associations with the airport across all visits; for this reason, we do not separate the analysis based upon whether the airport was used for departure, transit, or arrival on the previous trip, as the use of the most recent trip was only a mechanism for ensuring that participants were recalling brand associations with an airport they have used before.
The interview used open-ended questions to ensure that the airport associations that are recalled are already stored in participants' long-term memories and are not the result of self-generated validity, where participants might create associations in working memory as a result of participating in the study [43].It also relates to the use of a heterophenomenological epistemology, where we recognise that every individual participant lives in their own subjective reality [44].This subjective reality is important for understanding an individual's attitudes and behaviours even when it conflicts with objective realities (e.g., fear of flying vs. the objective reality that flying is the safest form of transport).Nonetheless, subjective realities can still be studied objectively through qualitative techniques [45][46][47].
After identifying the associations made with each airport, participants were asked what sorts of associations are important for choosing between airports, as "important associations", and why these associations are important.These questions provide a more generalised account of what is important for choosing between airports and are not specific to participants' most recent trips using air transport.However, a comparison can be made between the airport brand associations that participants actually made versus those that would maximise the likelihood of an air traveller choosing that airport over others.We recognise that in many instances, participants would have no choice over airports; however, this is still useful as a theoretical exercise to help understand what is important for participants when travelling through airports and is directly useful when choice does exist (such as in multi-airport zones, or when choosing between transit airports).

Analysis
The transcriptions of interviews were analysed using thematic analysis.These thematic analyses were conducted using Braun and Clarke's [48] 15-point checklist for a good thematic analysis, with five overarching stages in the process: transcription, coding, analysis, overall, and written report.Essentially, this involves collating qualitative answers for each question, allocating these to participants, and then defining common themes and classifying answers into themes.A more detailed summary of this method can be found in Table 2 of Braun and Clarke's [48] paper.Importantly, the themes have to be distinct from other themes and clearly defined to allow for replicability and to avoid double-counting.Participants could make multiple statements within an answer, meaning that they may provide statements that fall into different themes.These analyses produced themes and subthemes that help describe the discourse from participants that were interviewed.While the method employed is designed to describe what participants said, there is always a certain amount of interpretation based upon the context of each conversation.The analysis is somewhat weighted towards providing richer and more detailed accounts of the data to help provide airport managers with the level of detail required to make informed decisions.This also allows for many avenues for future research based upon the many different perspectives of participants, which may or may not be generalisable to wide portions of society.In particular, it will become obvious that some themes have contradictory comments from different participants, capturing that associations and determinants of airport choice are inherently subjective and unique to each individual's experience, aligning with the heterophenomenological epistemological stance taken in this research [44,45].

Participants 4.1.1. Demographic Information
There were 240 participants who completed the study, comprising participants from 35 different countries.This exceeded the minimum sample size requirement of 156 participants to achieve the required statistical power and also exceeded the target of at least 200 respondents.The mean age of the sample was 39.18 years (SD = 17.11, range 16 to 83).There were 105 males (43.75%) and 135 females (56.25%).Participants were primarily New Zealand citizens (153, 63.75%), with 81 foreign citizens (33.75%) and 6 dual citizens (2.5%).Table 1 summarises other key demographic variables.

Airport Information
This study summarises 642 airport visits, comprising 88 unique airports worldwide.The median duration for an airport visit was 1:00 h (IQR = 30 min to 2 h, range 2 min to 24 h).Table 2 summarises other airport characteristics, and a full list of airport visits that comprise the sample can be found in Appendix A.

Themes for Associations and Important Associations
A total of 2529 associations (1051 of which were unique) with airports were elicited from participants, with a mean of 3.94 associations per airport (SD = 2.77, Mdn = 3, range 0 to 18).A total of 971 important associations (394 of which were unique) for choosing between airports were also elicited from participants, with a mean of 4.05 important associations per participant (SD = 3.00, Mdn = 3, range 0 to 27).The thematic analysis revealed 13 themes for associations (which were also found for important associations), as well as those that could not be categorised.Each type of association and a description of it is presented in Table 3.Each of the 13 themes could be further broken down into subthemes, which can be viewed in in the tables contained within Appendix C.

Differences According to Airport Size
It is also possible to see how the proportion of associations within each theme changes according to airport size.Airports that serve greater numbers of passengers achieve economies of scale due to having larger commercial areas and a greater mix of retailers and food/beverage providers [50].Accordingly, there may also be differences in the nature of airport brand associations according to airport size.This is examined in Table 4, showing the percentage of associations in each theme for airports of different sizes.As can be seen, the facilities and infrastructure theme makes up the largest portion of associations regardless of airport size.However, there were also some interesting differences, such as mediumsized airports having fewer atmosphere associations (presumably because busyness was the largest subtheme, and they are neither busy nor quiet), literal and scenery and surrounds associations being less likely in large and very large airports (potentially because there is a greater variety of things inside the terminal to associate), and security associations being more common for large and very large airports (presumably due to greater numbers of international flights).

Statistical Significance and Effect Size of Themes
To examine the different themes in terms of their contribution towards brand associations and airport brand choice (in terms of important associations), single sample t-tests were run to test the number of associations and important associations against a value of 0 (see [51], Posten, 1979, for the procedure and robustness levels of this analysis method).For associations, this was calculated as the mean number of associations in each theme per airport per participant (i.e., the total number in each theme for each participant divided by their number of airport visits).For important associations, this was the raw number of important associations in each theme per participant.As the means for associations and important associations were slightly positively skewed, One-Sample Wilcoxon Signed Rank tests (with a Bonferroni correction) were also conducted using medians (e.g., see [52]).However, the results were the same in terms of which themes were statistically significant and are thus not reported.Table 5 shows the results of the single sample t-tests tests.* denotes statistical significance at the p < 0.0037 level, which is the equivalent to p < 0.05 level after applying a Bonferroni correction [53].Effect sizes can be interpreted as small (d = 0.2), medium (d = 0.5), or large (d = 0.8) [54].

Reasons for Important Associations
This study elicited 507 reasons (219 of which are unique) for why certain associations are important in choosing between airports, with a mean of 2.11 (SD = 1.33,Mdn = 2, range 0 to 7) reasons per participant.The thematic analysis revealed 14 types of reasons for why associations were important for choosing between airports; these along with their descriptions are shown in Table 6.Most of the reasons that underlie important associations are analogous with themes previously linked to related concepts like airport service quality and airport design, e.g., [55][56][57][58][59][60][61][62][63][64][65].The reasons are often related to multiple important associations across different themes; accordingly, this study does not provide subthemes for each type of reason.This is because the reasons are often intrinsically related back to the specific important associations of the participants.However, they capture the general theme behind each reason regardless of what specifically was important.To give airport managers an idea of what sorts of improvements at their airport they should prioritise and invest in, it is useful to examine the statistical significance and effect size for each of the reasons.Single sample t-tests were run to test the mean number of reasons against a value of 0. Ten participants were excluded from the tests because they had no important associations and therefore no reasons for important associations.As the mean for reasons was slightly positively skewed, One-Sample Wilcoxon Signed Rank tests (with a Bonferroni correction) were also conducted using medians.However, the results were the same in terms of which themes achieved statistical significance and are thus not reported.The results of the single-sample t-tests are shown in Table 7.
The results of Table 7 show that three themes have a medium effect size (to make travelling easier, emotion, and time), indicating that air passengers would like airports to make their travel experience as easy and seamless as possible, to keep them in a good state of mind emotionally (e.g., reduce stress of travel), and to minimise the amount of time they have to spend within the airport or in transit.However, aiming to reduce the time spent within the airport may seem somewhat self-defeating for airport managers given that they want passengers to spend money and buy goods and products within the airport terminal to maximise non-aeronautical revenue [66].Accordingly, a balancing act is needed between participant's desire to minimise time within airports and airport managers' imperative to maximise passenger revenues for the airport.[53].Effect sizes can be interpreted as small (d = 0.2), medium (d = 0.5), large (d = 0.8) [54].
Note that the mean reflects the mean number of reasons for each participant across the sample, so the 0.16 figure for comfort means that any given participant would have a 16% chance of having said a statement within that theme.
The other themes have small effect sizes but are all still statistically significant, except for past experiences.One that is particularly interesting is the idea that airports need to be empathetic towards their passengers.Many of the participants within this theme were specific to their circumstances and coming across airports that were particularly accommodating or unaccommodating.For example, some participants were smokers, some had children, and others were physically disabled.Having the appropriate facilities to accommodate their particular needs was important for these participants, and when such facilities were not present, those participants felt like the airport was unempathetic towards their circumstances and that affected their airport experience and satisfaction levels.

Reasons for Having No Important Associations
There were 10 participants who had no important associations with the airports in their most recent trip using air travel.Those participants were still probed with the "why" question and hence reasons for having no associations can be deduced.Four participants suggested that airports do not matter and that they would always just choose the quickest flight route to their destination; three participants noted that the only thing that matters is the location (e.g., city or country) they want to get to and they choose the airport that is most logical for that; two participants highlighted that they would choose an airline and would not be concerned with which airports they were routed through; and one participant said that airports were not important to them.

Additional Comments
There were 281 additional comments (233 of which were unique) made by 125 participants.These were divided into 13 themes as well as those that could not be further categorised.These are shown in Table 8.

The Fundamentals versus the 'Nice-to-Haves'
The results of this study highlight that it is the fundamental facilities and infrastructure provided by an airport that have the greatest effect upon the creation of the airport's brand associations and upon airport brand choice.The facilities and infrastructure theme accounted for the largest portion of associations (23.45%) and important associations (41.27%) and was found to have a statistically significant and large effect (see Tables 5 and 7) on the make-up of brand associations and the associations participants use to choose between airports.These findings should not be surprising considering that the very definition of an airport is a provider of aviation infrastructure [1].This does not discount the role of other sources of brand associations (e.g., customer service or atmosphere); however, it does highlight the need for airports to conduct their core business well.
While the results clearly show the diversity of association types that the participants made with airport brands, there is a clear difference between various themes in terms of their contribution toward the overall airport brand association structure and toward choosing between different airports.The findings of this study validate the findings of Kefallonitis and Kalligiannis [26] that airport service quality, shop variety, passenger lounges, and incorporating the culture, art, and architecture of a city are important aspects of airport branding.However, in this study, all of these aspects have a small effect size (d < 0.5) and would not likely be the core areas of focus of airport managers.In this sense, this study is consistent with Halpern's [25] finding that airport managers tend to focus on targeting specific airlines, modifying facilities and developing strategic marketing partnerships as opposed to promoting a recognised brand.The term "strategic marketing partnerships" for airports in the context of Halpern's [25] study meant collaboration with local business and tourism.In the context of this study, these strategic marketing partnerships could help with a number of the themes that rely on tenants or ancillary entities to provide the service (e.g., food and beverage, transport to the city, etc.).The recognised brand comes about through its associations, so the idea that airport managers are already focussed on fundamentals (e.g., facilities and infrastructure, food providers, transport providers, etc.) rather than the 'nice-to-haves' (e.g., artwork, scenery, customer service, etc.) emphasises that an airport brand cannot be separated from the travel experiences that passengers have travelling through airports that lead to brand associations.Ultimately, the brand associations that matter most to air travellers when choosing between airports come from these fundamentals more so than the 'nice-to-haves', again highlighting the importance of getting an airport's core business sorted prior to working on any of the 'nice-to-haves'.

Attitudes vs. Behaviours
This study examines airport brand choice in terms of the brand associations that are important for air travellers to choose between airports.This is an attitudinal measure that indicates the criteria that air travellers (i.e., the participants) might use to evaluate and choose between airports when planning their journey.However, attitudes do not always predict behaviours.For example, despite attitudinal concerns of air travellers towards air transport's role in anthropogenic climate change, most air travellers are unwilling to modify existing air travel behaviours [67,68].Nonetheless, behavioural measures also have drawbacks.For example, when examining brand loyalty, the use of only behavioural measures ignores the role of mental processes in forming loyalty and can conceal spurious brand loyalty, where the repeat purchase of the same brand may be due to a lack of availability rather than loyalty [69][70][71].While this phenomenon has not been directly observed for airports, spurious brand loyalty has been observed in airline markets [72][73][74].Thus, both attitudinal and behavioural measures are important in gaining a holistic understanding of air traveller behaviour when choosing between airports.
Because of the use of only attitudinal measures to examine how to maximise the likelihood of airport brand choice, this study does not capture some of the real-world constraints that will likely influence actual behaviours.In particular, this study finds that relatively small percentages of participants mentioned flight connectivity/frequency (3.33%), airline choice (18.75%), and airport accessibility (9.17%) as important associations for choosing between airports, with an additional nine (3.75%) participants giving these as reasons for having no important associations.Nonetheless, each of these has been shown to predict airport choice behaviours [75][76][77][78].
As Başar and Bhat [79] highlight, it is important to learn how air travellers form their consideration sets for airport choice (i.e., how they choose the set of airports to be considered, which happens prior to choosing one airport from that set).Geographic location can rule airports out of a consideration set, as ultimately, airports facilitate air travel to and from countries and cities, and ground accessibility to and from those locations must be realistic, otherwise the airport will not be under consideration [80,81].Following that, due to the effects of double jeopardy (i.e., the idea that small brands have smaller customer bases who are also less loyal, [82]), it is easier for air travellers to buy a flight that operates from an international hub airport with higher flight connectivity and flight frequency because there are more flight options available to purchase (and thus they are more likely to be in the consideration set), potentially explaining why flight connectivity and frequency are important for air travellers.This is similar to observations of double jeopardy within airline and transport markets [45,72,73,83].Finally, the different airports in the consideration set of air travellers may involve different airlines, where airline choice becomes a driving factor of airport choice.For example, air travellers may have to compromise with regard to airport choice due to the importance they place on factors such as airline type (legacy or low-cost carrier), airfare, total flight times (including transit time), meals, on-board flight service and entertainment, aircraft used, a particular airline, frequent flyer programmes, and so on, e.g., [63,84,85].
This section has highlighted that there may be a number of behavioural factors that are not fully captured within this study due to its focus on attitudinal measures.Nonetheless, understanding the mental processes that underlie airport brand choice is important to airport managers for understanding how air traveller behaviours can be changed in the future.While real-world constraints such as flight connectivity and airport accessibility will influence air traveller behaviours, those constraints may change over time.For example, changes in socio-political and economic status may result in rapid increases in flight connectivity [86,87].Similarly, ground access to airports may change due to improved or new ground transport options, expanding existing catchment areas for established airports [88,89].Accordingly, when these constraints that moderate behaviours change, air travellers' attitudes will influence how future behaviours will change in relation to those constraints [90], where future-oriented behaviours are better predicted by attitudes than near-future behaviours [91].This study thus contributes towards understanding the future-oriented behaviours of air travellers using attitudinal brand choice for airports.

Relating Airport Branding to Airport Service Quality
This study finds that airport customer service was only mentioned by 22.5% of participants as an important association for choosing between airports.This may appear lower than expected, based upon past research regarding the role of customer service in airport choice, e.g., see [31,92,93].However, this study was very strict in its boundaries around the customer service theme, limiting it to customer service directly from airport staff.The term 'airport service quality' is often used to indicate a much broader swathe of variables, including facilities, check-in, servicescape, security screening, ambience, concessions, wayfinding, total time, and satisfaction, e.g., compare the measures of [93][94][95].All of these factors are mentioned to varying degrees by participants during interviews; however, they are thematically grouped and divided into different themes (i.e., infrastructure/facilities, airline/flight, security, atmosphere, getting around, and evaluation).It is very likely that if this study had used the more encompassing idea of airport service quality, many of an airport's brand associations would be captured by the concept.Indeed, Paternoster [31] suggests that airport service quality and providing outstanding customer experiences are what turn 'typical' airports into unique brands.Given the wide range of brand associations that could be created from the activities of airport service quality, this suggestion is unsurprising.Nonetheless, the focus of this study was to aid managers in influencing brand associations rather than improving airport service quality.By delineating customer service provided by airport staff from those provided by other entities (e.g., airlines, shops, restaurants, etc.), it makes it clearer where airport brand associations are being sourced from, in turn aiding managers in influencing such associations.

Through the Compound Brand Lens
The results of this study highlight the importance of viewing airports through the lens of being compound brands [11].When examining the themes and the subthemes for both associations and important associations, it becomes clear that while the airport may be the source of many of the associations, other entities also act as sources for associations and important associations for airport brand choice.This may be very clear with themes such as airline/flight, security, cultural, and scenery and surrounds because these are primarily sourced from airlines, government agencies, and the cultural and geographic location (city, region, country, etc.) of the airport.However, it may also be less overt, such as the food/beverage subtheme within the wider facilities and infrastructure theme.For an airport to have positive associations within this subtheme, the airport would need to provide suitable and well-designed facilities for such services, but the actual tenants who occupy those spaces and sell the food and beverages to air passengers will also act as important sources of associations.In each sense, the brand associations of the airport are being multi-created by different entities.
This multi-creation of brand associations is also important when considering how air travellers choose which airports to travel through, with the infrastructure and facilities and the getting around themes having the largest effect among the themes.The former relies on the relationship between an airport and its tenants to ensure that the right infrastructure is not just being built by the airport but also occupied by the right tenants to ensure that the right facilities are available to passengers.This is consistent with past research in the airport management domain showing the interaction between airports and tenants in the provision of facilities, e.g., [66,96,97].Equally, the getting around theme relies not just on effective design of airport terminals and systems for air passengers to get around the airport (including between terminals) and the building of suitable facilities to allow for transfer from air transport to other modalities but also the availability of transport providers for passengers to transfer onto to get to their ultimate destination (e.g., taxis, buses, trains).Again, the importance of interactions between airports and ground transport providers has been emphasised by past research [98][99][100].In these two themes (i.e., the infrastructure and facilities and the getting around themes) with the largest influence upon airport choice, the associations that are used to choose between airports are again multi-created by different entities.The reasons for important associations may also relate back to tenants, although this could not be directly observed in this study.For example, providing entertainment, comfort, or empathy towards travellers may involve the provision of goods and services from the airport's tenants to meet these needs.
The importance of viewing airports as compound brands is not simply an academic exercise.When examining branding strategies for airports, it is important to consider where the airport is actually able to make a difference itself and where the airport may have only limited control.As mentioned above, past work in the field of airport branding has highlighted eight elements of airport branding strategies: (1) retail pricing strategies; (2) selection of retail outlets; (3) choice of food and beverage outlets; (4) architectural layout and design; (5) artwork; (6) services and entertainment; (7) service staff; and (8) airport logos, slogans, and wordmarks [28][29][30]101].While all but the last of these strategies (logos, slogans, and wordmarks) can be directly observed to have an effect in this study (i.e., there are similar terms within themes and subthemes, see subthemes in the tables within Appendix C), each of these strategies rely to varying degrees upon the assistance and cooperation of tenants and ancillary entities.For example, unless an airport is directly running the shops within its terminals, then retail pricing strategies are not something that the airport management would have direct control over.However, strategies like selecting retail outlets and food and beverage providers are areas that airport management does have direct control over.This diffusion of control is a unique characteristic of a compound brand [11] and is an important consideration alongside the relative importance of each strategy in terms of its contribution to airport brand associations and airport brand choice.

Practical Implications
Every airport has unique opportunities and challenges as well as finite resources.While the broad themes of airport brand associations and how they affect airport brand choice have been addressed, these show the 'big picture'.In Appendix C, all of these broad themes are broken down into specific associations.This provides a level of granularity and richness of data that allows airport managers to assess the relevance of particular associations for their airport.For example, some airport managers may be intrigued by the number of cultural associations air travellers make with airports.When examining Table A8, they will find that 2.5% of participants made associations with aspects of indigenous culture found at a particular airport (e.g., some participants referred to the tomokanga, a Māori carved gateway that arriving international passengers must walk through at Auckland Airport).While this may not be significant for many airports, for those that are situated where there are local indigenous peoples, incorporating aspects of indigenous culture into the design of the airport (e.g., airport terminals-arrival and departure halls) may be highly relevant.While this is merely a single example, there are many associations contained within the tables of Appendix C that airport managers can ponder over and assess the relevance of for their airport's particular situation.In this sense, airports can be thought of as similar to a place brand, where the language of the symbols (of which many will be sources of associations) contained within the airport environment will convey different things to different users to form an overall brand image [102].This may in turn prompt further investigation to assist in the prioritisation of resource allocation towards initiatives aimed in part at improving the favourability of brand associations for the airport, e.g., [103,104] but also how the airport communicates its benefits to potential passengers, taking a semiotic perspective, e.g., [102].Such a richness of data can only be gathered using qualitative techniques [105], the richness of which has already been identified as useful for processes such as new product development and examining brand identity creation [106,107].Gummesson [108], p. 309, highlight that "complexity, ambiguity, fuzziness, chaos, change, uncertainty and unpredictability are characteristics of a market economy", requiring qualitative marketing data to allow practitioners to make the right decisions.This study thus reiterates the practical usefulness of its qualitative approach, suggesting that the application of similar techniques to a particular airport would be very insightful for that airport's management.In the future, such themes elucidated from qualitative research may form the basis of thematic questionnaires or indicators to assess air traveller priorities for an airport or their assessment of an airport, in a similar vein to touristic studies looking at destinations [109,110].

Policy Implications
The theme of security was found to be a source of associations for 9.5% of airport visits, and 19.58% of participants had at least one important association for determining airport choice within this theme.In Table 3, one can see that 2.92% of participants had a bad experience with airport security and 5.83% of participants felt that the security was too strict during airport visits in their most recent trips.Conversely, when examining which security associations are important for choosing between airports, terms such as 'easiness' and 'expediency' are common (see Table A25).The difficulty with this theme is that airports have almost no control over airport security because airport security is typically the responsibility of a government agency [111,112].There are substantial differences between countries in terms of aspects such as levels of intervention, number and nature of checks, staffing and equipment budgets, and levels of discretion for security officials [113][114][115][116].In the United States, Gkritza, Niemeier, and Mannering [57] find that there are no systemic differences between airports in terms of passenger satisfaction, highlighting the influence of the federalised approach.Because security measures form a significant part of airport brand associations and are used by nearly one in every five participants for choosing between airports, this suggests that airports in countries with easier and seamless security systems will have more favourable brand associations and likelihood of brand choice.Airport management may need to lobby their governments accordingly as from the passengers' perspective, airport security is viewed as being part of the airport.This means that associations sourced from government security measures compound back to the airport brand itself, affecting the favourability of associations for the overall airport brand.

Conclusions
As airports become increasingly commercialised and seek non-aeronautical revenue, airport branding has become a more salient concern [29,32].However, the present literature on the topic provides a piecemeal application of the brand construct to airports.This study ameliorates this research gap by examining airport brands in terms of the associations that air passengers make with airports, which ones are important for choosing between airports, and why.In doing so, this study provides a holistic overview of airport branding.It also shows that the various themes identified in this study do not have a uniform effect upon airport brand association creation and airport brand choice and accordingly need to be prioritised.This study also views airports through the lens of being 'compound brands', which offers insight into the role of tenants and ancillary entities in creating airport brand associations and maximising the likelihood of airport brand choice.However, this study also affirms past research highlighting the importance of focussing on the fundamental business of airports: providing facilities and infrastructure.Accordingly, this study contributes to the literature on airport branding by providing a detailed account of airport brand association creation and airport brand choice through the compound brand lens.
To provide insights for airport managers, this study provides a detailed account of the sorts of associations that air passengers make with airports but also which ones are important for choosing between airports and why.Each airport has its own unique opportunities, strengths, and circumstances and so it is not possible to make blanket generalisations about how to best create and manage an airport's brand.However, the themes presented in this study are useful for understanding the sorts of associations that might be creating an airport's brand and also their relative importance.This study provides an approach that can be easily replicated for an airport to provide a snapshot of airport brand performance from an air traveller perspective.The same themes could be used by airport managers to help categorise associations, and the importance of each theme can be tested within the context of their airport.Similarly, by seeking to understand the reasons behind why some associations are important and others are not, airport managers can evaluate how certain strategic directions and opportunities may change the make-up of associations and the propensity for favourable airport brand choice.

Limitations and Future Research
While this study captured information from 240 different participants, incorporating 642 airport visits, it did take place within New Zealand and most of the airport visits discussed were of New Zealand airports.Accordingly, there may be differences in the findings if the research was replicated in other parts of the world.This would be an interesting opportunity to replicate the approach in this study in another country to see whether the results are comparable.In particular, future research may also focus on airport choice in a market with competition between specific primary and secondary airports or in a multi-airport region.These were not possible in this study due to the study location and the fact that participants could only talk about airports they travelled through in their journey.
This study has presented several themes for associations, important associations, and reasons for important associations for airport choice, but it did so based upon unaided recall.Using the data from this study to create survey instruments or other approaches to study the same topic using recognition (as opposed to recall) may yield different results.Indeed, both recognition and recall have been shown to produce different results in research areas such as advertising and price awareness, e.g., [117,118].However, as du Plessis [119], p. 90, observes, it is important to understand what recognition and recall each measure and the "shortcomings and strengths of the experimental environment one is applying" when using one or the other.
Another limitation of this study that has already been alluded to is that it has only used attitudinal measures to determine what are important for participants (i.e., air travellers) when choosing between airports.This was performed to avoid spurious brand loyalty, where behavioural constraints determine choice (e.g., only having one airport in the city or needing to transit through an airport to fly with a particular airline), from obfuscating what is important to consumers where genuine choice does exist (e.g., choice of transit hubs).While it would have been ideal to have behavioural measures to compare these to, past research has indicated that it is better to study one or the other (i.e., behavioural or attitudinal) and acknowledge that they measure different things, rather than try to combine the measures into a single study [120].Nonetheless, this does provide a potential avenue for future research to examine which airport brand associations are important in determining past behaviours (i.e., why they travelled through the airports they did on a particular trip), in a similar vein to what has been conducted with airline brand associations [72].

Appendix C.7. Experience
There was a total of 156 associations (95 of which were unique) that comprised the experience theme.This represents 6.17% of all associations, with 19.63% of airport visits involving the participants making at least one association within the theme.The experience theme represented 38 important associations (19 of which were unique), comprising 3.91% of important associations.A total of 13.75% of participants had at least one important association within this theme.The experience theme could be broken up into several smaller subthemes, which are shown in Tables A14 and A15.There was a total of 593 associations (168 of which were unique) that comprised the facilities and infrastructure theme.This represents 23.45% of all association, with 50.16% of airport visits involving the participants making at least one association within the theme.The facilities and infrastructure theme represented 403 important associations (120 of which were unique), comprising 41.5% of important associations.A total of 64.17% of participants had at least one important association within this theme.The facilities and infrastructure theme could be broken up into several smaller subthemes, which are shown in Tables A16 and A17.

Appendix C.13. Travel
There was a total of 251 associations (107 of which were unique) that comprised the travel theme.This represents 9.92% of all associations, with 28.04% of airport visits involving the participants making at least one association within the theme.The travel theme represented 4 important associations (all of which were unique), comprising 0.41% of important associations.A total of 1.67% of participants had at least one important association within this theme.The travel theme could be broken up into several smaller subthemes, which are shown in Tables A26 and A27.Appendix C.14. Uncategorised There were 17 associations and 10 important associations that could not be categorised into one of the aforementioned themes.

Figure 1 .
Figure 1.Illustration of how compound brands have associations from multiple sources.

Table 1 .
Demographic variables by number and percentage of participants.

Table 2 .
Airport variables by number and percentage of airport visits.

Table 3 .
Themes and their descriptions.

Table 4 .
Percentage of associations in each theme by airport size.

Table 5 .
Statistical significance and effect size for associations and important associations.

Table 6 .
Types of reasons and their descriptions.
1Does not sum to 100% because one participant may give more than one reason.

Table 7 .
Statistical significance and effect size for reasons and important associations.
* denotes statistical significance at the p < 0.0037 level, which is the equivalent to p < 0.05 level after applying a Bonferroni correction

Table 8 .
Themes for additional comments.

Table A13 .
Subthemes of important evaluation associations.

Table A15 .
Subthemes of important experience associations.

Table A16 .
Subthemes of facilities and infrastructure associations.

Table A17 .
Subthemes of important facilities and infrastructure associations.

Table A25 .
Subthemes of important security associations.

Table A27 .
Subthemes of important travel associations.