Marketing education for sustainable development

Purpose – Given the pressing global challenges underpinning the United Nations ’ Sustainable Development Goals, marketing managers can no longer focus only on purely economic outcomes but must simultaneously respond to social and environmental concerns. This requires the teaching of new competencies in marketing education, as also re ﬂ ected in today ’ s accreditation requirements for business schools. Therefore, this paper aims to explore how current research into marketing education incorporates sustainable development. Design/methodology/approach – Through a bibliometric literature review – examining 71 publications using the bibliographic coupling method – the current research front in marketing education is analysed. Findings – This paper identi ﬁ es seven trending topics in marketing education research that both highlight a currently prevalent sustainability gap in marketing education research and – when combined into a framework – help marketing education researchers and educators to address this gap. Originality/value – This paper extends the already established concept of education for sustainable development to include the concept of marketing education for sustainable development (MESD) for the ﬁ rst time. The MESD framework combines its raison d ’ être with guidance on how sustainable development should be taught and what the learning objectives should be for future marketing managers.

Educaci on en marketing para el desarrollo sostenible Resumen Prop osito -Dados los apremiantes retos mundiales que sustentan los Objetivos de Desarrollo Sostenible (ODS) de las Naciones Unidas, los directores de marketing ya no pueden centrarse únicamente en los resultados puramente econ omicos, sino que deben responder simult aneamente a las preocupaciones sociales y medioambientales. Esto requiere la enseñanza de nuevas competencias en la educaci on de marketing, como tambi en se refleja en los requisitos de acreditaci on actuales para las escuelas de negocios. Por lo tanto, este documento explorar a c omo la investigaci on actual sobre la educaci on en marketing incorpora el desarrollo sostenible.
Metodología -A trav es de una revisi on bibliom etrica de la literatura -examinando 71 publicaciones mediante el m etodo de acoplamiento bibliogr afico-se analiza el frente actual de la investigaci on en educaci on en marketing.
Resultados -En este artículo se identifican siete temas de tendencia en la investigaci on sobre educaci on en marketing que ponen de manifiesto una laguna en materia de sostenibilidad que prevalece actualmente en la investigaci on sobre educaci on en marketing y que, combinados en un marco, ayudan a los investigadores y educadores en educaci on en marketing a abordar esta laguna.
Originalidad -Este artículo amplía el concepto ya establecido de Educaci on para el Desarrollo Sostenible (EDS) para incluir por primera vez el concepto de Educaci on en Marketing para el Desarrollo Sostenible (EMDS). El marco EMDS combina su raz on de ser con orientaciones sobre c omo debe enseñarse el desarrollo sostenible y cu ales deben ser los objetivos de aprendizaje para los futuros directores de marketing.

Introduction
Overcoming sustainability challenges is essential to protect our planet and safeguard livelihoods while meeting the needs of the world's current and future populations [United Nations Department of Economic and Social Affairs (UNDESA), 2021; United Nations General Assembly (UN), 1987]. Consequently, accrediting bodies for higher education require that business schools "respond to the business world's changing needs by providing relevant knowledge and skills" (AACSB Business Accreditation Standards, 2020) and "to be actively engaged in promoting business ideas and solutions to sustainability challenges" (EQUIS Standards and Criteria, 2021). In the context of business education, marketing has a critical role to play because it has a direct impact on social and environmental conditionsfar more than some other business disciplines (Kemper and Ballantine, 2019). Based on its ability to influence behaviour, marketing is well positioned to help reduce unsustainable SJME practices and promote sustainable development in both businesses and society more generally (Gordon et al., 2011). Not integrating sustainability into marketing degree programmes risks making the discipline increasingly irrelevant in today's world  and wasting its potential to contribute to the forging of a sustainable world (Chandy et al., 2021).
This study examines whether current research supports the raison d'être of sustainability in marketing education and to what extent it provides guidance for the practical implementation of integrating sustainability into marketing education. Using a bibliometric approach, we explore the following research questions. In terms of sustainability and according to research, what is taught in marketing education and how is it being taught?
This study's contribution lies in the identification of seven trending topics in marketing education research thatwhile recognising sustainable development as a force shaping marketinghighlight a currently prevalent sustainability gap. The paper thus introduces the concept of marketing education for sustainable development (MESD) and presents a framework for bridging that gap. The MESD framework recommends that marketing degree programmesusing the United Nations' Sustainable Development Goals (SDGs) as guiding principles and applying experiential learning as well as internet-based and online educationprovide students with key competencies for sustainable development.
The remainder of this paper is organised as follows. Firstly, the theoretical background on sustainability and sustainable development, education and marketingplus their interrelationshipsis presented in detail. This is followed by an elaboration on the applied methodology and the results of the bibliometric literature analysis. Lastly, the MESD framework is presented, theoretical and educational implications are discussed, including possible limitations, and suggestions for future research opportunities are made.

Theoretical background 2.1 Sustainability and sustainable development
The concept of sustainability usually describes the balance between the three dimensions of economic, social and environmental [United Nations Department of Economic and Social Affairs (UNDESA), 2021]. In this study, sustainability is defined as the state in which this balance is achieved. Sustainable development is understood as processes that pursue this balance while meeting "the needs of the present without limiting the ability of future generations to meet their own needs" [United Nations General Assembly (UN), 1987, p. 43]. Although the concepts of sustainability and sustainable development are not new, they have steadily gained importance in politics, society and science over recent decades, especially in the light of increasingly drastic climate predictions and the already apparent consequences of climate change (Leal Filho et al., 2018). In 2015, the United Nations operationalised sustainable development into 17 goals to be achieved by 2030. These SGDs (see Appendix - Table A1) are also known as the 2030 Agenda. The SGDs are a shared expression of the needs of stakeholders at the global level and can serve as both an indication and a measure for progress towards the overarching objective of sustainability (Fonseca and Carvalho, 2019;Fonseca et al., 2020;Giangrande et al., 2019).
While knowledge and research about sustainable development is increasingly available, this has not stopped humanity from pushing the limits of exploiting natural resources. This brings on urgency to the debate in sustainable development research, with a particular focus on the SDGs (Leal Filho et al., 2018).

Education for sustainable development
Education plays a vital role in achieving the SDGs. SDG 4 particularly targets the promotion of Education for Sustainable Development (ESD), which involves the acquisition of knowledge, Marketing education skills and abilities that enable learners to make informed choices and act responsibly to help achieve a sustainable environment, economic sustainability and a more just society (Giangrande et al., 2019). SDG 4 also links the other goals of the 2030 Agenda because education trains change agents that help develop and implement ideas to address the problems underlying the SDGs [Redman and Wiek, 2021;United Nations Educational, Scientific and Cultural Organization (UNESCO), 2017;Hübscher et al., 2021]. Many of these problems will be easier to address once more effective knowledge-based infrastructures are in place (Boeren, 2019), and education contributes to the creation of such infrastructures (Voola et al., 2022). This view is supported by Fonseca et al. (2020) who found that SDG 4 is a goal that shows strong positive correlation with most of the other SDGs.
In line with the aim of SDG 4 to promote ESD, Redman and Wiek (2021; see also Wiek et al., 2011) developed a framework to guide ESD and proposed a set of eight key competencies for sustainable development (hereinafter referred to as "SD competencies"): (1) systems-thinking competence to allow the understanding of complex socialecological systems and their dynamics; (2) futures-thinking competence to allow envisioning the future; (3) values-thinking competence to allow the evaluation of whether a current or future state of a system is sustainable, and to take into account concepts of justice, integrity and ethics; (4) strategies-thinking competence to allow the construction of action plans to help achieve greater sustainability; (5) implementation competence to allow plans to be put into action and to adapt them as necessary; (6) interpersonal competence to allow collaboration with others and to involve them in advancing action plans; (7) intrapersonal competence to allow caring for oneself while advancing sustainability; and (8) integration competence to facilitate the integration of planning competencies with collaboration and self-caring competencies to successfully implement action plans.
Moreover, the framework by Redman and Wiek (2021) includes complementary competencies (disciplinary competencies; general competencies, such as critical thinking and creativity; and professional competencies, such as communication) that are already widely applied. Redman and Wiek (2021) argue that their framework "links science, education, and society in the joint effort of broadening and accelerating transformations towards the Sustainable Development Goals" and serves as a base "from which to build off and specify learning objectives" for educating change agents in disciplines with relevance to sustainability.

The role of marketing in sustainable development
The relevance of the marketing discipline to sustainability can be traced back to the 1970swhen the broader scope of marketing was recognised and the impact that marketing can have on social and environmental conditions was first highlighted (Kelley, 1971). Within research, there are usually two perspectives on the impact of marketing on sustainability. On the one hand, marketing is seen as contradictory to sustainable development. This reflects a view of marketing based on purely economic outcomes, e.g. ever-increasing SJME consumption through exploiting natural resources (Kemper and Ballantine, 2019). On the other hand, by promoting the development of sustainable products and behaviours, marketing can bring about desirable changes in individual consumers, businesses and society towards sustainable development (Chandy et al., 2021;de Ruyter et al., 2022). Such a broader scope of marketing beyond economic outcomes is also reflected in the latest definition of marketing used by the American Marketing Association, which states that marketing should also create value for society as a whole [American Marketing Association (AMA), 2017].
Throughout this paper, we take the stance that marketing has great potential to create positive impacts on sustainable development and thus on the SDGs. Although marketing scholars have begun to focus on this potential to contribute to sustainability (de Ruyter et al., 2022;Voola et al., 2022), we aim to explore whether marketing education research is also moving beyond the belief that marketing's purpose is solely to create economic value . Thus, the following sections present a thorough bibliometric review of the marketing education literature.

Research design and strategy
To shed light on current marketing education research and, more importantly, to identify how it incorporates sustainable development, the literature review method was chosen. Literature reviews are especially useful when the amount of literature within a field is rapidly growing while remaining fragmented and/or interdisciplinary (Snyder, 2019). According to Ferrell and Ferrell (2020), marketing is such a fragmented field with many different areas of research interest such as consumer behaviour, digital marketing and macro-marketing approaches. Systematic literature reviews help to gain and systematise collective knowledge about research fields and, through a theoretical synthesis, uncover new trends as well as suggesting important topics for future study to inspire further development of the field. To be considered systematic, the review of the literature must follow predefined steps and rules to be reproducible and to minimise both bias and error (Tranfield et al., 2003;Wawak et al., 2020). One type of systematic review is the bibliometric literature review. That applies quantitative methods to bibliometric data to rigorously map the intellectual structure and evolutionary nuances of well-established research fields (Donthu et al., 2021). For this study, we followed the steps for a bibliometric review as proposed by Donthu et al. (2021).

Sampling
Ideally, the data collected for this study should create a picture of marketing education research that is as complete as possible, but also of high quality. To find all relevant publications, the search process was informed by the PRISMA guidelines (Moher et al., 2009).
3.2.1 Identification. The final keyword search conducted in November 2021 considered the following search string: TITLE-ABS-KEY ("marketing higher education" OR "marketing education" OR "educat* marketers" OR "educat* marketing manager*" OR "Marketing Curriculum" OR "Marketing Course*" OR "Marketing Pedagogy"). This resulted in 1,273 records in the Scopus database and 577 records in the Web of Science (WoS) database, which are both major sources for citation (Mongeon and Paul-Hus, 2016). The search was refined by limiting records to English-language publications and papers from journals of the first and second quartiles in either marketing or education according to the Scimago Journal Ranking (Scimago, 2021), which led to 760 records in Scopus and 230 records in WoS making it to the screening stage.
3.2.2 Screening. The abstracts andif the abstract was not sufficiently informativefull texts of the retrieved records were screened manually to remove duplicate papers and those that did not address the education of marketers, but instead examined, for example, the administrative marketing departments of higher education institutions. The records were further refined by limiting the time range from when the 2030 Agenda (and so the SDGs) were adopted in 2015 to the end of 2021 (when the analysis was conducted). Lastly, records from Scopus were preferred over those from WoS because more individual titles were found in Scopus, although there was still a large overlap between the two databases, leaving 186 records. Such overlap has also previously been observed in many other studies (Mongeon and Paul-Hus, 2016).
3.2.3 Inclusion. To make sure that only trending and impactful topics were revealed, only papers that had received at least five citations were considered for analysis. The sample size was thus reduced to 76 papers. An initial analysis using the bibliographic coupling method revealed that five of these 76 papers had no references in common with the rest of the sample and were therefore excluded. This led to 71 key papers forming the final sample (see Appendix - Table A2).

Analysis
To uncover trends in marketing education research and to address the question of what is taught in terms of sustainability and how it is being taught, a combination of: performance and network analyses and content analysis is applied.
Performance analysis is a common practice in bibliometric reviews. Although descriptive, it underscores the importance of the various components of a research field (such as authors, journals or papers) by providing a proxy for productivity, impact and influence. As part of the performance analysis, the top authors, journals and papers were identified based on metrics such as the number of papers that one author or journal produced as well as the number of citations that the papers received (Donthu et al., 2021). Network analysis was carried out using bibliographic coupling. That identifies research clusters based on the similarity of publications as measured by the number of references that such publications share. The resulting clusters present the latest developments within a field, in the form of trending themes (Aria and Cuccurullo, 2017; Donthu et al., 2021).
The identified clusters were further investigated using content analysis that used the TCCM model as a structurereferring to theory (T), context (C), characteristics (C) and methodology (M) (Paul and Rosado-Serrano, 2019). In addition, each cluster was assessed in terms of its contribution to the SDGs as an indication and measure for sustainable development and to the SD competencies as an indication for the integration of ESD (Sustainable development evaluation).
The Bibliometrix package in RStudio version 2021.09.1, the VOSviewer version 1.6.17 and Microsoft Excel were used for data analysis and visualisation of the results.

Results
The 71 papers included in the analysis were written by 170 authors and published in 19 journals between 2015 and 2021. Performance analysis revealed that the authors with the highest number of publications in the sample almost all represent affiliations in Englishspeaking countries such as the USA. Unsurprisingly, the Journal of Marketing Education published by far the most papers on the topic of marketing education. This journal also provided all ten of the most cited papers included in this study, most of which have a focus SJME on digital topics, such as the integration of social media in the marketing curriculum . Among the journals with more than one publication in the sample, only one journal makes an explicit reference to the SDGs in the description of its aims and scope. Some journals at least invite submissions that deal with the interrelation of marketing and society, such as the discipline's changing role in the face of resource limitations and society's responsibility to future generations.
Applying bibliographic coupling to the sample of this study resulted in seven research clusters (see Figure 1). The clusters' names were chosen on the basis of terms frequently used in titles, abstracts and keywords of papers within the cluster. The results of the content analysis are presented per cluster.

Cluster 1: forces shaping marketing
The first cluster includes publications (n = 17) that deal with the various forces that potentially shape the marketing discipline and therefore are also likely to have an impact on marketing education. These forces include technological advances, socioeconomic change and geopolitical change .
4.1.1 Theory. Learning theories (such as social constructivism, social cognitive theory, experiential learning theories) and marketing theories (such as product lifecycle theory, service-dominant logic) were commonly used to inform research in this cluster.
4.1.2 Context. Most research in this cluster took place in English-speaking countries. Forces driving change in marketing education are core to the context of the first cluster. These include digital transformation, above all; the extended responsibility of businesses; and students' and educators' roles in marketing. Some of the authors specifically chose to examine sustainability aspects within marketing education Markley Rountree and Koernig, 2015).
4.1.3 Characteristics. Factors that have been investigated by studies in this cluster included students' awareness and perception regarding the changes in the marketing environment and measures of students' academic performance and learning outcomes. Many of the researchers representing this cluster applied quasiexperimental designs and cases to identify how marketing courses respond to the changing marketing environment (Markley . Others used mixed methods based on interview and survey data. Quantitative analyses were also reported that had been carried out on the basis of course syllabi or students' essays and journals . 4.1.5 Sustainable development evaluation. In Cluster 1, some publications present possible ways of contributing to the achievement of SDG 4target 4.7, which is to mainstream ESD, for example through modified curricula. The contributions of Grier (2020)in terms of improving understanding of diversitycould be linked to SDGs 5 and 10 and Rust (2020)in terms of identified research opportunitiescould be linked to SDGs 10, 12 and 13. Perera and Hewege (2016) explicitly mention the SDGs in their introduction, but do not elaborate on the goals towards the end of their paper. Regarding the SD competencies, their findings could be understood as a call for systems-thinking ("undergraduates find it difficult to view the social function of international business firms from a holistic point of view"), values-thinking ["(undergraduates find it difficult to) critically assess sustainable marketing practices"], strategies and futures-thinking ["(undergraduates find it difficult to) articulate futuristic views on sustainable marketing practice"].

Cluster 2: employability and work-readiness
Research in the second cluster (n = 13) is concerned with what employers seek in marketing graduates and how marketing graduates can best serve their employers.
4.2.1 Theory. Research in this cluster was embedded in extensive literature reviews. Bacon (2017), for example, used human capital theory to inform his research, while Anderson and Lees (2016) applied social practice theory. Various regression models were used to underpin the results in this cluster.
4.2.2 Context. The discussion about the economic value of marketing education provided the context for this cluster. In many publications, the relevance was underlined by the digital and technological changes in marketing practice. Studies were carried out using mainly US-based samples. The Australian and British higher education landscape provided the context for two studies. In contrast to the context of developed countries, the study by Teklehaimanot et al. (2017) was embedded in the discussion of the skills needed in Ethiopia.
4.2.3 Characteristics. The value of marketing education was measured through, for example, income and students' career satisfaction (Bacon, 2017), the importance of skills to practitioners  and the perceived and actual value of skill change throughout university marketing degree programmes .
4.2.4 Methodology. Methodological approaches included qualitative (e.g. case studies) as well as quantitative techniques (e.g. multiple regression analyses). Quantitative methods based on survey data were used most frequently.
4.2.5 Sustainable development evaluation. Questions of employability are closely related to SDG 8, though this SDG was not specifically mentioned in any of the papers. The second cluster makes an explicit reference to the digital skills required in those marketing jobs  that involve disciplinary competence. Other scholars in this cluster focus on employers' need for more general and professional competencies, such as collaboration, communication and both critical and creative thinking skills DeLong and Elbeck, 2017).

Cluster 3: experiential learning
The study of various pedagogical approaches that involve active learning, such as roleplaying and games, is the focus of this cluster (n = 9).
4.3.1 Theory. Experiential learning theory (Kolb and Kolb, 2005) is the common theme of papers in this cluster. The only paper that proposes another theory as its core is by Dahl et al. (2018) who apply critical thinking theory. Yet, their results are again set in relation to experiential learning because experiential learning as a pedagogical approach is widely believed to foster critical thinking skills .
4.3.2 Context. Various marketing courses at mainly US-based institutions are studied in the context of the increasing linkage between marketing and information technology. For example, while information technology can advance pedagogical approaches that involve experiential learning (such as games), it has also spurred new teaching content (such as search engine optimisation), making it difficult for teachers to achieve the optimum breadth and depth of topics .
4.3.3 Characteristics. Papers belonging to this cluster evaluate marketing pedagogies, for example, regarding their impact on students' motivation  or students' acquisition of discipline-specific knowledge Mills and Treen, 2016) and critical thinking skills . Characteristics include perceived student learning (what students think they have learnt) and actual student learning (typically expressed in grades).
4.3.4 Methodology. Evaluations of pedagogical approaches are mainly based on surveys among students. The results are, in many cases, presented together with a detailed description of the respective exercise or learning activity, often even including a step-by-step "how to" guide for teachers who aim to include such exercises or activities in their own courses.
4.3.5 Sustainable development evaluation. In Cluster 3, Radford et al. (2015) address SDG 4target 4.7 on ESD implementation by calling on marketing educators to use experiential learning to specifically teach systems thinkingone of the SD competenciesto foster an understanding of marketing's broader societal role. Other papers in the cluster provide evidence for the positive effect of experiential learning on general competencies such as critical thinking. Kemp et al. (2019) findings relate to strategies thinking competence, but not in a sustainability context.

Cluster 4: marketing simulation
In terms of content, this cluster (n = 9) is closely related to Cluster 3. Like experiential learning, simulations within marketing courses add a practical, real-world element to a course.
4.4.1 Theory. Some studies were based on situated learning theory and social constructivist theory. Others incorporated flow theory. However, not all studies were informed by any particular theory, though they did all include comprehensive literature reviews.
4.4.2 Context. The samples used in the studies represent a more diverse background in terms of the countries from which they were drawn (such as Portugal), although they are still predominantly from English-speaking countries. The papers' content is driven by ideas of how to alter the delivery of content and improve student performance, as well as by the various means of maintaining student engagement and motivation, both based on the shift from "teaching as instruction" to "student-centred learning".

Marketing education
4.4.3 Characteristics. Student course performance and/or task mastery orientationtogether with factors such as enjoyment, motivation, transfer of knowledge and real-world applicability, among othersare the characteristics common in this cluster.
4.4.4 Methodology. Papers in this cluster make use of both qualitative and quantitative analyses of courses that implemented a marketing simulation. In some cases, experimental groups were compared with control groups not exposed to simulation. Data was collected from interviews, surveys and students' project reports. Duffy and Ney (2015) and  collected data from educators and marketing practitioners, thereby adding another valuable perspective.
4.4.5 Sustainable development evaluation. If at all, studies' findings in the fourth cluster can be seen as contributing to knowledge about how to tackle challenges underlying target 4a of SDG4, namely, to build and upgrade education facilities to improve learning environments.  argues that letting students engage with the real world lets them experience its complexities, and hence fosters systems thinking competence.  and Humphrey et al. (2021) propose a notion of learning that is perceived as a general competence. Duffy and Ney (2015) associate the acquisition of general and professional competencies, such as critical thinking and communication skills, with the integration of simulation activities into marketing education. Several other authors also emphasise the need for teamwork in simulation and game-based education, thereby indirectly dealing with interpersonal competence.

Cluster 5: social media and internet-based education
Cluster 5 (n = 10) is primarily concerned with digital interfaces that are intended to facilitate teamwork and communication.
4.5.1 Theory. Two studies applied the technology acceptance model (TAM) to frame their investigations into using a technology tool as an alternative or complementary means of instruction. However, the other studies did not mention a specific theory.
4.5.2 Context. The publications in this cluster mainly deal with US samples. However, three studies include samples from outside the USA (reflections of students from the UK, Barn, 2016; business schools across the globe, Shaltoni, 2016; and instructors from around the world, Muñoz and Wood, 2015). Driven by the opportunities presented by digital transformation, many of the scholars aim to challenge the limitations of a formal curriculum or classroom and extend the context to more informal learning environments (Barn, 2016). Brocato et al. (2015), among others, highlight how the internet has transformed the marketing landscape and what the resulting implications are for marketing education. Research in this cluster centres around questions of how social media can best be integrated into course content  or be used as a pedagogical tool (Abney et al., 2019). 4.5.3 Characteristics. For the application of technological tools (including social media) as a medium of instruction, perceived usefulness and perceived ease of use were the measures applied. Researchers also investigated the engagement of students towards the class, group or instructor, as well as perceived student learning outcomes.
4.5.4 Methodology. Methodologies applied in this cluster were mainly qualitative analyses of student reflections and/or quantitative analyses based on survey data. Only  analysed the content of e-marketing textbooks and titles of e-marketing programmes offered at business schools.
4.5.5 Sustainable development evaluation. Studies in the fifth cluster that use (for example) social media to extend course settings beyond the fixed classroom contribute to an understanding of how to build and upgrade education facilities to improve learning SJME environments (SDG4target 4a). Due to the predominantly digital context of the studies, this cluster provides ideas about how to improve ICT skills (SDG 4target 4.4). Cluster 5 is mainly devoted to improving teamwork and communication through the application of alternative digital interfaces, thereby leading to the conclusion that professional (communication) and interpersonal (collaboration) competencies are fostered through internet-based education.

Cluster 6: digital literacy
According to the authors who published papers assigned to the sixth cluster (n = 8), the marketing discipline is encountering many digital challenges, such as the use of Big Data. Hence, the marketing curriculum should reflect the need for improved analytical skills .
4.6.1 Theory. Theoretical frameworks in this cluster were represented by learning theories and Foucault's classic power/knowledge construct. However, while claiming to be informed by previous research, many of the papers make no mention of theory.
4.6.2 Context. Again, samples within this cluster were mainly from within the USA, except for Snuggs and Jevons (2018) who concentrated on the Australian higher education sector. The internet, Big Data and other technological advances were all reported to influence the skill set required of marketing graduates and necessitate that curricula be adapted to meet today's digital challenges. There is also a particular focus on the gap between training and practice. One factor cited as leading to this gap is faculty who (having been educated before the advent of the internet) often lack sufficient expertise in the use of technologies and data and are therefore unable to adequately teach about their use. 4.6.3 Characteristics. Studies were carried out based on student learning outcomes related to technology "savviness" (such as comfort in the use of tools) and on course content and delivery (such as integrated vs standalone courses), as well as on supporting factors (such as faculty).
4.6.4 Methodology. Methodologies ranged from qualitative studies and mixed methods (surveys and focus groups) to descriptive cases. 4.6.5 Sustainable development evaluation. Studies in the sixth cluster have improved our understanding of ICT skills' improvement (SDG 4target 4.4). Although digital literacy, as considered in this cluster, is not directly linked with one of the SD competencies, it could be linked to the disciplinary competencies needed for marketing in general. To acquire improved digital literacy, Rohm et al. (2021) and Spiller and Tuten (2015) call on marketing courses to foster creativity, communication, critical thinking and collaborative skills. Particularly worth mentioning is the publication by Walker and Moran (2018) who suggest applying a social science lens to courses to deliver an understanding of ethics and social responsibility (relating to values thinking) as well as to how social problems affect individuals, communities and societies (relating to systems thinking). According to Liu and Levin (2018), forecasting (relating to futures thinking) is an essential competence in marketing when it comes to the handling and evaluation of data.

Cluster 7: online education
Four of five papers in the seventh cluster (n = 5) deal with teaching marketing online, such as using online videos as the means of instruction. 4.7.1 Theory. Most publications in this final cluster are not based on any specific theory. Indeed, the publication by  is the only one that addresses a concrete model (input-process-output model of team behaviour) and frames the study in terms of social identity theory and self-categorisation theory.
Marketing education 4.7.2 Context. The focus of studies is on marketing courses offered mainly at universities in the USA. Here too, the context is driven by the opportunities brought about by digital transformation. In general, the application of online teaching methods is regarded positively, and  even ascribe superior performance in exams to it. However, other scholars  suggest that faculty appear to be hesitant or concerned about using online teaching, whether for time, cost or technical reasons. 4.7.3 Characteristics. Rajamma and Sciandra (2020) identified the factors influencing the success of team teaching as contribution, planning and coordination and course implementation. Other papers used measures such as student performance, attitudes, satisfaction and group cohesion. 4.7.4 Methodology. Four publications used a quasi-experimental design comparing online or blended teaching methods with traditional face-to-face teaching for the same course. Rajamma and Sciandra (2020) performed qualitative research, interviewing five faculty members involved in the planning and delivery of an online team-taught marketing course. 4.7.5 Sustainable development evaluation. Two of the studies mentioned how the use of online teaching methods can reduce gender disparities, which reflects SDG 4target 4.5, and SDG 5. Rajamma and Sciandra (2020) offer a prescriptive example for marketing educators to overcome challenges in online team teaching, which can be indirectly seen as a contribution to SDG 4target 4c, namely, to increase the supply of qualified teachers in that it offers practical guidance for university faculty. This cluster can also be related to the improvement of ICT skills (SDG 4target 4.4).  found that student projects that are conducted in an online environment improved the quality of communication and group cohesion. Where groups and communication are concerned, one can relate these findings to interpersonal competence and the complementary professional competencies. Therefore, online teachingtogether with other methods of instructionseems to have potential in fostering SD competencies.

Towards a framework for integrating sustainable development into marketing education
Summarising the results of the bibliometric analysis, this study finds that in current marketing education research, sustainability is recognised as a shaping force in marketing, while digital transformation dominates the discussion. Both trends provide a rationale for what should be taught in marketing education and how it should be taught. However, the SDGs and SD competencies are currently given little or no consideration in the marketing education literature. This study thus identifies a sustainability gap in marketing education research. The results of the content analysis help to address this gap as well as questions about teaching content and pedagogical tools. We synthesise the results into a guiding framework that combines the raison d'être (WHY) with guidance on how SD should be taught (HOW) and what the learning objectives should be for future marketing managers (WHAT; see Figure 2). The framework extends the already established concept of ESD to include the concept of MESD for the first time. By integrating the SDGs and the SD competencies, the framework has the potential to support marketing in contributing to the forging of a sustainable world and to respond to the demands of SDG 4 and accrediting bodies to provide knowledge and skills that provide ideas about and solutions to sustainability challenges. SJME 5.1 Why marketing education for sustainable development? Based on the findings from Cluster 1, it is important that the framework acknowledges that digital transformation is not the only force shaping marketing. Although digital transformation can be associated with some SDGs (e.g. SDG 9), it represents only a small chunk of the SD spectrum (represented as the inner circle of the marketing education environment in the framework). The SDGs, as the operationalisation of SD (allencompassing outer circle of the marketing education environment), are part of an international agreement and can thus offer a concrete purpose to students. The framework therefore includes the SDGs as guiding principles for what and how marketing students should be taught.

WHAT should be taught?
The SDGs provide guidance on the various sustainability topics about which students need knowledge. New course content should be created directly in the context of single or multiple SDGs, existing course content should be adapted accordingly. However, knowledge of the SDGs alone will not be enough for marketing students to promote and contribute to sustainable development. The SD competencies as proposed by Redman and Wiek (2021) must be included in the framework as learning objectives. The performance of marketing students should be measured in terms of these key competencies. Current marketing education research emphasises the importance of critical thinking, creativity and communication. These are vital complementary skills. Cluster 2 shows that digital skills are important for marketing graduates to stay relevant in the workplace. Clusters 5 and 6 support that finding. The framework therefore also includes digital literacy as a learning objective of MESD. How these competencies can be fostered is discussed below.

HOW should it be taught?
Experiential learning and marketing simulations are particularly promising when it comes to acquiring SD competencies and are thus included in the framework. Clusters 3 and 4 Marketing education support this view and demonstrate that adding real-life experiences to marketing courses is particularly important. These pedagogical approaches should be embedded in a sustainability context. Digital transformation is part of facilitating sustainable development.
Internet-based and online education should therefore not be neglected or discounted in marketing education. Such pedagogical approaches not only promote the acquisition of SD competencies and digital literacy, but also offer universities the opportunity to become more resource-efficient (e.g. through savings on campus costs) and thus contribute to university sustainability. The MESD framework leads to several implications for marketing education theory and practice, which are presented below and conclude this study.

Conclusion
Given the pressing global challenges underpinning the SDGs, marketing managers can no longer only focus on purely economic outcomes but must simultaneously respond to social and environmental concerns. Marketing managers should therefore be equipped with SD competencies. This study explored whether current research supports the raison d'être of sustainability in marketing education and to what extent it provides guidance on the integration of sustainability into marketing education, addressing the following research questions. In terms of sustainability and according to research, what is taught in marketing education and how is it being taught?
Seven trending topics in marketing education research were identified that highlight a currently prevalent sustainability gap in marketing education research. However, when the results of these clusters are combined into a framework for MESD, they also provide the basis for marketing education researchers and educators to address this gap. The MESD framework recommends that marketing degree programmesusing the United Nations' SDGs as guiding principles and applying experiential learning as well as internet-based and online educationprovide students with key competencies for sustainable development.
Several implications for marketing education researchers and educators were drawn and those are described below.

Theoretical implications
Previous research has shown that SD is a priority that the marketing discipline should not neglect. In this study, it was found that, context-wise, most current research in marketing education is dominated by digital transformation. Overall, it was expected that at least the more recent publications in the sample would have addressed the SDGs given the time that has already passed since the adoption of the 2030 Agenda. None of the publications examined claims to make a direct and concrete contribution to any of the SDGs. This now offers substantial opportunities for future research. The SDGs can help provide a sustainability context for future studies. For example, it might be worthwhile to investigate what specific contribution marketing education can make to one particular SDG. One way to encourage a reorientation of context towards SD within marketing education research could be to update the aims and scope of journals and to explicitly include topics such as the SDGs.
Even though the acquisition of some of the SD competencies has been indirectly researched, efforts should now be made to examine specifically the more transformative of the competencies (futures-, values-and strategies thinking), as these remain among the least discussed in marketing education research. Future marketing education research should further refine or even challenge the MESD framework. For example, the addition of other SJME competencies or the extent to which individual competencies of the framework are interdependent should be investigated.
Another avenue for future research must be the pedagogical approaches to promoting the SD competencies. We suggest building on previous research about experiential learning as well as internet-based and online education and specifically testing the pedagogies' effectiveness in sustainability contexts.
In terms of context, the studies looked at for this research were predominantly conducted in the USA or other developed countries. Mongeon and Paul-Hus (2016) found that Englishlanguage journals and publications are overrepresented within the Scopus database, so a concentration on contexts from English-speaking countries is inevitable but leads to a limitation in this study. Voola et al. (2022) remind us that the challenges presented by the SDGs are greatest in the least developed countries. Therefore, the context of future studies should be chosen accordingly.
Measuresas investigated under "Characteristics"used in future research will depend on the aims of individual studies. However, where student learning is concerned, future research should find ways to measure actual student learning (as distinct from perceived student learning) to be able to provide more accurate information on, for example, learning's contribution to helping to achieve the SDGs.
Regarding methodology, future research should keep up with the selected methods' diversity and use mixed methods to empirically test outcomes, such as the effectiveness of marketing pedagogies in helping to promote sustainable development. Regarding the methodological approach applied in this paper, it must be mentioned that, while the bibliometric method is said to mitigate bias in literature reviews, it does not come without its limitations: the bibliometric method depends on the availability and correctness of the data provided in the database. For seven publications, full texts could not be retrieved. That could have had an impact on the results obtained from content analysis. Scholars have previously argued that bibliographic coupling cannot tell whether two papers citing a third one refer to the same information in the third paper or whether to contradictory information (Weinberg, 1974). However, we argue that this is mitigated by the extensive content analysis. Nevertheless, future research may support and challenge the findings of this study with other approaches and complement the results with findings from research published in conference proceedings, books and other media.
Lastly, scholars in the field of marketing education are strongly encouraged to embed their research in theories and then to test such theories. According to Lindgreen et al. (2021), challenging, contrasting and refuting theories is an opportunity to arrive at original and courageous research findings that further advance the field.

Educational implications
Regarding guidance for the practical implementation of integrating sustainability into marketing education, the MESD framework recommends that marketing degree programmesusing the SDGs as guiding principles and applying experiential learning as well as internet-based and online educationprovide students with key competencies for sustainable development. The SD competencies should be adopted by marketing educators as learning objectives. Marketing educators can use this study's findings about pedagogical approaches to help design courses that deliver on these learning objectives. However, measures must be identified that can track student's performance regarding the acquisition of these SD competencies. Business schools can benefit from delivering marketing courses in a sustainability context. The SDGs point to several topics that can be addressed in addition to Marketing education traditional curriculum content. At the same time, the SDGsas representing an international agreementcan also provide a purpose to students.
In conclusion, we encourage business schools, and marketing faculty in particular, to consider the above recommendations to help transform students into change agents who can contribute to marketing's huge potential for achieving a more sustainable future, thereby also meeting the demands of SDG4 and current accreditation standards. We call on marketing education researchers and marketing educators to build on our findings, to continuously develop the MESD framework and find ways to implement and test it in practice. To end hunger, achieve food security and improved nutrition and promote sustainable agriculture #3 Good Health and Well-Being To ensure healthy lives and promote well-being for all at all ages #4 Quality Education To ensure inclusive and equitable quality education and promote lifelong learning opportunities for all #5 Gender Equality To achieve gender equality and empower all women and girls #6 Clean Water and Sanitation To ensure availability and sustainable management of water and sanitation for all #7 Affordable and Clean Energy To ensure access to affordable, reliable, sustainable and modern energy for all #8 Decent Work and Economic Growth To promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all #9 Industry, Innovation and Infrastructure To build resilient infrastructure, promote inclusive and sustainable industrialisation and foster innovation #10 Reduced Inequalities To reduce inequality within and among countries #11 Sustainable Cities and Communities To make cities and human settlements inclusive, safe, resilient and sustainable #12 Responsible Consumption and Production To ensure sustainable consumption and production patterns #13 Climate Action To take urgent action to combat climate change and its impacts #14 Life below Water To conserve and sustainably use the oceans, seas and marine resources for sustainable development #15 Life on Land To protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification and halt and reverse land degradation and halt biodiversity loss #16 Peace, Justice and Strong Institutions To promote peaceful and inclusive societies for sustainable development, provide access to justice for all and build effective, accountable and inclusive institutions at all levels #17 Partnership for the Goals To strengthen the means of implementation and revitalise the global partnership for sustainable development Source: Authors' own work SJME