International services marketing: an integrative assessment of the literature国际化服务行业市场营销：综合文献分析

ABSTRACT Despite the considerable importance of the services sector in international marketing, scholarly research in the area is limited and unsystematic. This article examines the domain and literature of international services marketing in 41 academic journals from 1999 to 2018 and provides a future research agenda. The investigation reveals 942 published articles, or approximately 2% of all articles published in the journals during the period. Research in the area is under-represented, particularly in premier journals. Scholarly use of theories, models, and other theoretical perspectives is relatively sparse. We devise an integrative summary of thematic areas and contrast this with the revealed literature. After identifying the top publication outlets for recent research, we highlight the most salient theoretical perspectives and thematic areas. This article identifies gaps in the literature, proposes a research agenda, and specifies avenues for advancing scholarship in international services marketing.


Introduction
Historically, international business has entailed companies that make and sell tangible products. However, firms that produce intangible services have become important players in international marketing. International services are efforts, deeds, and performances conducted across national borders in critical contact with foreign cultures (Clark et al., 1996;La et al., 2009). Services have unique characteristics that require developing specific knowledge and methods and give rise to distinctive challenges in international marketing (Bolton & Myers, 2003;Javalgi & Martin, 2007;Parasuraman et al., 1985;Pauwels & de Ruyter, 2004;Vargo & Lusch, 2004). Thus, international services marketing is a distinctive field in marketing practice and scholarship.
Services account for approximately two-thirds of world economic output and are the fastest-growing economic sector worldwide (Central Intelligence Agency, 2016;World Trade Organization, 2017). Because of their nature, internationalization of services has progressed more slowly than for products (e.g. Clark et al., 1996;Pauwels & de Ruyter, 2004). However, world exports of commercial services amounted to US$4.8 trillion in 2016, accounting for nearly one-quarter of all international trade (World Trade Organization, 2017). Services trade is accelerating and is especially notable in the United States, the United Kingdom, many European Union countries, and India. These countries represent almost two-thirds of combined inward and outward stocks of service sector foreign direct investment (FDI) (UNCTAD, 2017;World Trade Organization, 2017). Under globalization, fewer services firms can escape market confrontation with foreign competitors. Services play a critical role in the value chains of most firms and in national economic development. Furthermore, services are central in the global value chain, and they offer opportunities not only for multinational enterprises but also for small and mediumsized enterprises from emerging markets (Malhotra et al., 2005;World Trade Organization, 2017). Managers and scholars increasingly view services as the fundamental component of economic exchange (e.g. Vargo & Lusch, 2004).
Internationalization of the services sector has coincided with the emergence of scholarly research. In his article, Knight (1999) reviewed the literature on international services marketing from 1980 to 1998. He uncovered just 124 articles from a crosssection of 31 journals in marketing and international business. The literature was descriptive, often focusing on particular countries or industries, with relatively little development of constructs, models, and theories (Knight, 1999). Other scholars have noted deficiencies in research on international services marketing (Javalgi & Martin, 2007;Malhotra et al., 2005), and some have questioned the applicability of theoretical perspectives rooted in the literature on tangible products to services (e.g. Clark et al., 1996;Dahringer, 1991;Goerzen & Makino, 2007). Recent assessments of the exporting literature also do not specifically mention the topic of services (Kahiya, 2018;Paul et al., 2017).
The broad range of international services activities, in both research and practice across multiple sources of producer-buyer value, suggests considerable fragmentation in the marketing field (Javalgi & Martin, 2007;Knight, 1999). Overcoming fragmentation in any field requires systematic reviews to ascertain whether differences within a domain are authentic (Rousseau et al., 2008). A systematic review should explicitly summarize what is known and not known about scholarship and practice (Rousseau et al., 2008). Given the enormous role of services in global trade and the sheer scope of investments in cross-national services activities, a greater understanding of international services marketing is necessary. Such understanding can elucidate how international services marketing affects products, consumers, and other business stakeholders.
Given the paucity of thematic review articles in the field of marketing and international business (Palmatier et al., 2018;Paul, 2017), the value of an integrative assessment of the international services marketing literature is manifold. Review articles undertake critical evaluations, and they identify and synthesize relevant literature (Palmatier et al., 2018). As understanding of state-of-the-art research findings in the topical domain is vital, review articles with an integrative stance can serve as a valuable basis for scholars. Furthermore, integrative reviews provide promising avenues for future research, creating a roadmap of extant knowledge and allowing innovative ideas to develop. Thus, systematic assessments of the literature contribute to the discipline's progress (Bueno et al., 2019;Palmatier et al., 2018;Paul, 2017;. The current study has multiple objectives: (1) to examine the domain and literature on international services marketing from 1999 to 2018; (2) to devise an integrative summary of thematic areas and contrast this with the revealed literature; (3) to identify the top publication outlets for recent research; (4) to examine the characteristics, including strengths and potential pitfalls, of extant research; (5) to identify and examine relevant models and other theoretical perspectives in the field; (6) to identify research gaps, opportunities, and notable trends, delineating where the field stands and establish points of departure; and (7) to map a research agenda, including questions for future research. In essence, this study endeavors to provide an integrative understanding of the field and a roadmap for innovative research ideas, as stated previously regarding the nature of a thorough assessment. The presentation of theoretical frameworks and a research agenda is state of the art in academic research (e.g. Belanche et al., 2020). This research thus contributes to the advancement of the discipline by highlighting promising research gaps through a critical synthesis of the relevant literature.
The next section provides background on international services marketing. After summarizing the methodology used herein, we provide descriptive and specific research findings. We close by reviewing gaps in the literature and examining major issues in the status of research on international services marketing. Varadarajan (2010) highlighted the importance of delineating the domain of scholarly fields such as marketing, the limitations of such endeavors, and the need to periodically revisit the issue, given the evolving nature of the field. Figure 1 summarizes representative thematic areas in international services marketing. We systematically identified these areas while reviewing the 41 journals used in this study, consistent with extant concepts, activities, and phenomena in international marketing and services marketing (e.g. Cavusgil et al., 2005;Clark et al., 1996;Grönroos, 2007;Javalgi & Martin, 2007;Knight, 1999;Swartz & Iacobucci, 2000;Varadarajan, 2010;Zhang et al., 2008). In the course of conducting the review, we classified the areas into major research categories.

Background on the field
Many scholars have highlighted the challenges inherent in delineating the domain of any field (e.g. Varadarajan, 2010), particularly an evolving, dynamic field such as international services marketing. The thematic areas delineated in Figure 1 are representative; they are not intended to constitute a complete mapping of international services marketing. The aim is to describe, in a parsimonious and useful manner, the state of scholarship in international services marketing and guide scholarship in the field. As a managerial practice, international services marketing has existed for centuries. As a distinct field of study, however, the field has gained momentum only in recent decades (e.g. Javalgi & Martin, 2007;Knight, 1999). Within this contemporary time frame, scholars have explored myriad dimensions of international services marketing.
In Figure 1, the bi-directional links from box A to boxes 1-7 highlight dimensions associated with international services and the organizational environment and functions of marketing, related to orientations, strategy, management, processes, tactics, and the marketing mix, as well as specific dimensions of the service encounter. The center box also links to organizational performance, strategies and tactics of firm internationalization, and external environmental dimensions of international business. Box A highlights the role of describing, understanding, explaining, predicting, developing, and using theory, constructs, methods, and other aspects pertinent to research on international services marketing. Box A also points to research fields in which scholarship on international services marketing might be framed from extant theoretical domains, including economics, psychology, marketing, international business, and others. Overall, the figure summarizes representative organizational, inter-organizational, and environmental phenomena.
The bi-directional arrows in Figure 1 imply conceptual links, not directional relationships. For example, the bi-directional arrow from box A to box 3 denotes areas related to the marketing mix and marketing tactics. Specifically, branding, service characteristics, customization, pricing, distribution and channels, and communications are among the salient phenomena of international services marketing as a field of study. The conceptual links only appear in reference to box A to ensure a parsimonious exposition. For example, although the thematic areas in box 2 (strategy, management, and processes) are applicable in the context of nearly all the areas indicated in the other boxes, the figure does not show the conceptual links between box 2 and box 1 and from boxes 2-7. We next briefly elaborate the phenomena delineated in the figure.
While some aspects of the corporate environment and activities are specific to the domains of business, marketing, and the services sector, other aspects span multiple levels. Organizational environment and activities are fashioned by managers and other decision makers in the firm who orchestrate its behavior in the marketplace (Varadarajan, 2010;Varadarajan & Clark, 1994). Accordingly, the decisions managers make and their subsequent execution manifest as company activities in the marketplace. Figure 1 suggests how scholars might examine the role of organizational culture and orientations on the international marketing of services (box 1). Market orientation, learning orientation, and relationship marketing are among the performance antecedents of marketing, as recognized in extant literature (see Varadarajan, 2010). For example, separate from tangible products, marketing services internationally usually requires greater effort to develop customer relationships (Goerzen & Makino, 2007). Service marketers deal with a complex global environment, with vast opportunities and challenges (Reinsdorf & Slaughter, 2009). Strategy, management, and processes identified in mainstream marketing research play vital roles in creating and promoting services internationally (box 2). Among such activities, managers undertake market research, segment and target markets, and position their offerings to markets comprising consumers, other businesses, and other types of buyers (e.g. Clark et al., 1996;Grönroos, 2007;Knight, 1999;Swartz & Iacobucci, 2000;Varadarajan, 2010). Marketers devise strategic approaches and manage marketing activities that, internationally, occasion the need to adapt or standardize service offerings, often in an integration-responsiveness framework (Bartlett & Ghoshal, 1989). Important operational phenomena in international services include control, service productivity, and service failure and recovery. Marketers manage demand and service processes, often eliciting customer participation, and usually employ the Internet, telecommunications, information technology, or self-service platforms (Varadarajan, 2010). Achieving performance goals necessitates superior operational skills and leveraging technology to attain competitive advantage (Clark et al., 1996;Goerzen & Makino, 2007;Wang & Altinay, 2008).
The marketing mix and tactical issues include branding, characteristics of services (e.g. quality, value, degree of interaction with customers), pricing, distribution, and communications (box 3 in Figure 1). Intangibility, inseparability, perishability, and heterogeneity  are central to international service firms and influence the marketing mix and tactics (e.g. Aharoni & Nachum, 2000;Blomstermo et al., 2006). For example, intangibility limits firms' ability to patent, communicate, or set pricing on services (Bolton & Myers, 2003;Dahringer, 1991). Marketing challenges attendant to the nature of services are compounded internationally by linguistic, sociocultural, technological, economic, physical, and political-legal factors (Clark et al., 1996;Dahringer, 1991).
The service encounter is characterized by, but is not limited to, service development and design, the service delivery system, service operations, service provider(s), and the servicescape (box 4 in Figure 1). A key dimension of services marketing is consumer and business buyer behavior, such as waiting and complaining (e.g. Grönroos, 2007;Swartz & Iacobucci, 2000;Varadarajan, 2010). Understanding consumer behavior and other service encounter dimensions is critical because they are strongly susceptible to and influenced by culture and other factors in international environments (e.g. Winsted, 1997). Service providers are 'culture bearers,' usually embedded in the contexts in which services are marketed abroad, interacting directly in simultaneous production and consumption with consumers (Clark et al., 1996;Dahringer, 1991).
Services firms undertake internationalization (box 5 in Figure 1), which includes licensing and franchising (e.g. Altinay, 2006;, exporting and importing, global sourcing and offshoring, collaborative arrangements, FDI, and market expansion (e.g. Kiss et al., 2012;Clark et al., 1996). Internationalization approaches differ between manufactured products and services because of the latter's unique characteristics (Capar & Kotabe, 2003;Clark et al., 1996;Goerzen & Makino, 2007). Most services cannot be exported (Goerzen & Makino, 2007), helping explain why services are less dominant than products in international trade. While product manufacturers can internationalize gradually (Johanson & Vahlne, 1977), most services firms cannot export their offerings and may advance directly to FDI, a relatively risky and costly market entry strategy (Boddewyn et al., 1986;Goerzen & Makino, 2007).
Both practitioners and scholars emphasize organizational performance, which typically relates to value creation, purchase intentions, customer satisfaction, customer retention and loyalty, sales and profitability, and performance measurement (box 6 in Figure 1). Managers must devise innovative ideas and approaches to meet new international challenges and optimize organizational performance (Cavusgil et al., 2005).
Phenomena such as those enumerated in boxes 1-6 in Figure 1 exist in an external environment characterized by general environmental dimensions, including government intervention and international trade barriers and legal, regulatory, political, institutional, technological, linguistic and cultural elements (box 7). Characteristics of individual countries play critical roles in the provision and consumption of services (e.g. Dahringer, 1991;Malhotra et al., 2005;Mattila, 1999;Smith & Reynolds, 2002;Zhang et al., 2008). For example, substantial interaction between providers and consumers increases the role of cultural factors in international services marketing (Mattila, 1999). Services constructs may be perceived differently in different cultures. Consumer responses to service quality and the servicescape exhibit substantial cross-national variance (Keillor et al., 2004). Services are marketed to consumers, firms, and governments in advanced, emerging, and developing economies (e.g. Cavusgil et al., 2005;Clark et al., 1996;Jain et al., 2019). In the following sections, we examine the state of scholarship in international services marketing, providing insights into the structure of extant research as a basis for future research.

Methodology
This research examines the literature in international services marketing during the 1999-2018 period. We analyzed this period for two reasons. First, we wanted to follow up on Knight's (1999) study, which reviews the literature from 1980 to 1998. Second, the most recent and completely available year at the time of analysis was 2018. We employed a systematic approach to identify the journals for analysis, based on several criteria. First, we chose journals that focus on services, marketing, and/or international business. Second, we chose journals that together represent a relatively complete and diverse collection of publishing outlets, thus ensuring inclusion of the most salient articles on international services marketing. Third, each journal needed to be available from online library sources, such as ABI/INFORM, ProQuest, and EBSCO Business Complete. Fourth, we favored journals with an impact factor determined by Journal Citation Reports, which quantifies the degree of influence by measuring the journal's average number of article citations in extant research. Finally, we consulted six academics, well established in services, marketing, or international business, and asked them to identify journals they believed should be included. By following these criteria, we identified 41 journals, which represent an extensive inventory of the most important academic outlets for published research on international services marketing. This procedure is based on Knight's (1999) approach and is in line with recent publications presenting systematic literature reviews in the international marketing field (e.g. Paul & Rosado-Serrano, 2019). Table 1 displays the final list of journals used in the study, along with their impact factors. Journal Citation Reports did not provide an impact factor for two journals included in this study: Advances in International Marketing and International Review of Retail Distribution and Consumer Research. However, these journals have published many articles on international services marketing, and several of the academics surveyed argued for their inclusion. We excluded journals dealing generally with tourism, such as Tourism Management and Annals of Tourism Research. Considering the nature of tourism, most of the articles in these journals relate to international services marketing. However, we believed their inclusion would bias the findings toward the distinctive field of tourism.
In conducting the search, we decided against doing a keyword search (e.g. 'international services'), as we deemed it insufficient for uncovering all relevant articles. Instead, we examined the title, abstract, article keywords, and, if necessary, the full text in all the journals. As a further check, we scanned the reference sections of key articles for additional, relevant citations, ensuring that every chosen article was related to three keywords: 'international,' 'services,' and 'marketing.' Each chosen article was stored using a standardized file name. We coded key information in each article consistent with appropriate content analysis procedures (Kassarjian, 1977;Krippendorff, 1980), an approach used by scholars to conduct similar studies (e.g. He et al., 2008;Leonidou & Katsikeas, 2010;Peloza & Shang, 2011). We coded the information manually using a specially developed protocol, ensuring reliable data collection of the source and nature of articles, author information, research design, research scope, methodology, theoretical perspectives, and thematic areas. Examples of the coded material are the essential research method employed (conceptual/empirical and specific details) or the unit of analysis (firms/consumers/other), which is in line with state-of-the-art approaches in the literature (e.g. Peloza & Shang, 2011).
We computed inter-coder reliabilities using the percentage of agreement, or the ratio of agreements to the total number of coding decisions. The two coders attained over 90% agreement on all coding decisions. As a further step, we held additional discussion sessions, in which 95% agreement was achieved. As a reliability check, we randomly chose 10% of the total sample of articles, achieving more than 92% agreement in comparing this random sample (e.g. Perreault & Leigh, 1989). We transferred the resulting information in each article to a special coding sheet and then compared the resulting data to ascertain possible differences in their evaluations. We discussed any discrepancies, misunderstandings, or problems in the coding process, to reach mutual agreement.
Next, we created a database with categories of information to collect in the articles, such as 'main theories used,' 'types of services analyzed,' 'essential methods used,' 'units of analyses,' and 'name of countries involved.' We entered the relevant information from each article into the database for further analysis and then generated information from the resulting data.

Findings
The aforementioned procedure resulted in the discovery of 942 articles on international services marketing from 1999 to 2018. In total, the 41 chosen journals published approximately 44,356 articles during the period. Thus, the 942 articles on international services marketing represent approximately 2% of the total articles published in the journals in the period. This indicates that research on international services marketing is remarkably sparse, despite the importance of services in global trade, investment, and economic development. Table 2  The quantity and proportion of published research on international services marketing appears to have increased over time, though somewhat unevenly, with a recent decrease. We found 35 articles in 1999, 34 in 2000, 24 in 2001, 28 in 2002, 21 in 2003, 42 in 2004, 47 in 2005, 43 in 2006, 56 in 2007, 49 in 2008, 61 in 2009, 40 in 2010, 67 in 2011, 58 in 2012, 69 in 2013, 77 in 2014, 55 in 2015, 52 in 2016, 42 in 2017, and 42 in 2018. Over time, more scholars have been working in the area, and journal editors may have been more open to publishing their research. However, the findings suggest that research in the area remains sparse. Table 3 summarizes the theoretical perspectives that scholars have taken in their research. Some 419 articles of the 942 total works contained no distinguishable theoretical perspective. Among the remaining articles, the most common theoretical perspective was international culture, featured in 142 articles, especially using Hofstede's (1980) framework of cultural types. The next most frequently used theoretical approach was firm internationalization (e.g. Johanson & Vahlne, 1977), accounting for 129 articles, 13 of which emphasized internalization and FDI (e.g. Buckley & Casson, 1976), 11 the stages view (e.g. Cavusgil, 1980), and 10 Dunning's (1988) eclectic paradigm. Some 41 articles emphasized services-related theoretical perspectives (e.g. Zeithaml et al., 1985). Another 27 articles emphasized the resource-based view (Barney, 1991;Seggie & Griffith, 2008), followed by 15 articles emphasizing institutional theory (e.g. Kostova et al., 2008) and 13 articles each using the technology acceptance model (e.g. Davis, 1989) and transaction cost perspectives (e.g. Williamson, 1985). Finally, 11 articles used contingency theory (e.g. Donaldson, 2001), and 10 used agency theory. It is important to note that many articles incorporated two or more theoretical perspectives. Table 4 summarizes the service thematic areas and corresponding major theoretical perspectives and representative citations, among the 942 articles. We identify consumer behavior/perceptions and retail internationalization as the most prominent thematic areas, with 112 and 107 articles, respectively, and each area accounting for almost 17.1% and 16.3% of the total articles. Next were the areas of perception or evaluation of service quality (75 articles, 11.5%) and international market entry (54 articles, 8.2%). Other important service thematic areas were international advertising and general firm internationalization, each accounting for 7.9% and 7.3% of the uncovered articles, respectively.
We also examined the types of services analyzed in the studies. The most frequently investigated service industries were retailing (289 articles, 30.7%), banking and finance (95 articles, 10.1%), advertising (76 articles, 8.1%), and restaurants (49 articles, 5.2%). The remaining articles emphasized industries accounting for 5% or less of the research, ranging from export intermediaries to professional services to telecommunications. In terms of the unit of analysis employed in the 942 articles, 356 (37.8%) used the firm. Consumers were the unit of analysis in 262 articles (27.8%), and managers accounted for 58 articles (6.2%). In the 266 remaining articles, some other entity (e.g. articles, advertisements, transactions) served as the unit of analysis. Table 5 summarizes the essential research or analytical method used in the 942 articles. In total, 875 articles, or approximately 93%, were empirical works, 438 (46.5%) of which used surveys as the basis for data collection. Another 67 articles (7.1%) were non-empirical conceptual contributions. Some 135 articles (14.3%) used structural equation modeling as the main analytical tool, and 67 (7.1%) used regression analysis. Approximately 14% (131 articles) employed case study research, and 10.3% (97 articles) were based on secondary data. The remaining analytical methods are listed in the table.
For empirical work, Table 6 summarizes the countries used for collecting data or other information. The United States was the base country in 213 articles, followed by the United Kingdom (128 articles), China (121 articles), Germany (67 articles), Australia (48 articles), South Korea and Japan (47 articles each), India (45 articles), France (43 articles), Spain (42), Canada (35 articles), and all others. The articles examined 85 countries in total, some including multiple countries in Europe, Latin America, and Asia. We found a growing trend in research toward emerging economies, such as China and India (e.g. Elg et al., 2008;Malhotra et al., 2005;Paul & Gupta, 2014). While the United States, Western Europe, and Japan have been the sites of most research on international services marketing since 1999, emerging markets are playing a growing role.

Discussion
This research examines extant literature from 1999 to 2018 in 41 academic journals on international services marketing. We developed the study in relation to thematic areas represented in Figure 1, in an effort to deepen understanding of the field by examining what is known and not known about scholarship and practice. The findings revealed  942 published articles on international services marketing in the period. Though indicating progress in the field, the revealed works represent just 2% of all articles published in the 41 journals during the period. We identified the top authors and institutions in recent research; highlighted the most common theoretical perspectives, methods, and service areas; and summarized how research has evolved over time.
Broadly, the findings suggest that scholars have neglected services-focused organizations that market their offerings internationally. The domain of scholarly literature in marketing can be characterized in terms of geographic scope and essential focus. The explicit or implicit focus in marketing research to date usually has been on organizations that offer tangible products. In addition, many scholars have published tangible products-oriented marketing research in an international context. Finally, scholars have increasingly published general or domestically focused marketing research with a services orientation. However, much less research in the quadrant of organizations has emphasized the marketing of services internationally. Scholarship in this latter area remains at an early stage. This finding is surprising in light of services' enormous impact in global commerce (Malhotra et al., 2005;UNCTAD, 2017;World Trade Organization, 2017) and the numerous calls for further research (e.g. Javalgi & Martin, 2007;Knight, 1999;Malhotra , 2005). The sheer volume of services offered internationally implies that international services marketing is an important phenomenon, but the literature in this area remains scant. For example, Kahiya (2018) and Paul et al. (2017) do not mention services as a distinct research avenue in their assessment of exporting literature.
The findings also indicate that scholarly use of theories, models, and other theoretical perspectives in international services marketing research is relatively sparse. This is in line with other recent statements on the fragmented field of international business in general   128  3  China  121  4  Germany  67  5  Australia  48  6  Korea  47  6  Japan  47  8  India  45  9  France  43  10  Spain  42  11  Canada  35  12  Italy  30  13  Taiwan  29  14  Sweden  28  15  Singapore  24  16  Netherlands  22  17  Thailand  18  18  Russia  15  18  Brazil  15  18  Austria  15  21 New Zealand 14 22 Mexico 12 Note: Only countries employed in 12 or more articles are included in the table.
that is characterized by theoretical shortcomings (Paul & Sánchez-Morcilio, 2019). Many scholars have neglected to develop theoretical foundations on which to build or explain their research. This is unfortunate given the importance of theory to developing scholarly works (e.g. Deshpandé, 1983) and regular calls for using appropriate theory to support marketing and international research (e.g. Clark et al., 1996;Javalgi & Martin, 2007). Extant research in the field is biased in favor of a logical positivist paradigm that emphasizes theory testing over theory development. Lacking an appropriate focus on rich explanatory theories, development of scholarly understanding in international services marketing will suffer.
In this investigation, the majority of discovered articles (93%) were empirical works. More than half the studies used quantitative surveys and sophisticated analytical methods such as regression analysis or structural equation modeling. In the accepted paradigm for scholarly research, however, advanced empirical studies that test hypotheses should be reserved for research in relatively advanced fields (e.g. Deshpandé, 1983). Scholarship in a young field, by contrast, should emphasize exploratory research geared toward defining, identifying, and explaining key concepts and basic phenomena. Research should aim to develop constructs and theory that lay the foundation for subsequent empirical research (e.g. Deshpandé, 1983;Hunt, 1990). In this early phase of inquiry on international services marketing, extensive use of confirmatory research methods may be premature. In most of the thematic areas identified, more exploratory research is necessary to formulate and enhance under-developed concepts, constructs, relationships, and theory. Research using well-designed case studies, for example, would help clarify constructs, frameworks, and relationships. Ultimately, international services marketing needs a substantive balance of both qualitative and quantitative research methods to develop truly useful knowledge in the field.
As reflected in Table 2, we also found that research in higher-quality marketing or international business journals is comparatively scarce. This may imply that international services marketing holds little interest to scholars generally or to editors at top journals. At the same time, the investigation suggests that scholarship in the area often does not reach the high standards demanded by top outlets. This may be due partly to the research challenges inherent in international services marketing. Compared with research on tangible products, defining and measuring international services concepts pose important challenges. For example, many services are conveyed via telecommunications and the Internet. Delineating the international dimension of such offerings is challenging. Residency, transaction location, and who or what crosses national boundaries all complicate the problem of definition. In addition, the sheer variety and complexity of services activities may confound efforts to develop or apply externally valid theories and explanations. Research also may be complicated by the intangible, inseparable, perishable, and heterogeneous dimensions of services. Inseparability means that services usually must be provided at the customer's location. The culturally sensitive dimension of services likely poses particular challenges to scholars as they try to define and operationalize constructs and construct measures.

Research agenda
The findings indicate that research on international services marketing is significantly under-developed. In the following sections, we highlight gaps in the literature and offer suggestions for future research. We discuss additional issues for advancing scholarship in international services marketing organized in a framework consisting of the thematic domain, the contextual domain, and the methodological domain, in line with previous studies (e.g. Paul et al., 2017).

Thematic domain
We suggest directions for research in the thematic domain in the summary of thematic areas in Figure 1. Briefly, these include research on organizational culture and orientations; strategy, management, and processes; marketing mix and tactics; service encounter dimensions; internationalization strategies; organizational performance; and the firm's external environment. Table 5 identifies thematic areas most emphasized in extant research. In order of occurrence, scholars have focused most on the thematic areas of consumer behavior or perception, retail internationalization, perception or evaluation of service quality, international market entry, international advertising, firm internationalization, global sourcing or offshoring, organizational performance, marketing strategy, innovation, relationship marketing, tourism, technology acceptance or adoption, standardization versus adaptation, and supply chain management. These themes account for nearly two-thirds of research in 1999-2018. Comparison of the findings with the summary in Figure 1 reveals specific thematic areas neglected in scholarly research. We next highlight research gaps and suggest areas in which scholars can focus future research in the thematic domain.
Specifically, in the category of organizational culture and orientation (box 1 in Figure  1), the findings reveal that scholars have substantially examined relationship marketing and customer relationships. However, scant research has explored the roles of market orientation, learning organization, marketing ethics, corporate social responsibility (CSR), or sustainability in international services marketing. Recent literature in this area does not specifically discuss services (e.g. Zeriti et al., 2014). Other culture and orientation issues not addressed in Figure 1 may be appropriate for future research.
In the category strategy, management, and processes (box 2 in Figure 1), scholars have investigated marketing strategy issues such as target markets, general strategic approaches, standardization versus adaptation, and the use of technology in marketing services abroad. However, more work is necessary in these areas. For example, how should firms configure marketing activities at the global, regional, and local levels of consumption? Companies increasingly favor global and regional strategies that emphasize standardized offerings and delivery mechanisms. Substantial opportunities exist to investigate international segmentation, targeting, and positioning of services. Much work remains in addressing marketing management of international services. Another neglected area is international sourcing and management of services supply chains. This topic has gained importance as firms source more services from suppliers in emerging markets and elsewhere. Scholarly research is also necessary in international operational phenomena, including service processes, control, and service failure and recovery. Much general research has emphasized the role of customer participation in the creation and offering of services (e.g. Vargo & Lusch, 2004). However, scant research has assessed consumers' role in services internationally. Extant literature also considers the role in international services of technology, such as information technology, the Internet, and e-commerce, but work remains in this area.
The marketing mix and marketing tactics are another area for future research (box 3 in Figure 1). Scholars have substantially investigated international services quality issues, advertising in international communications, and the role of networks and retailing in global distribution channels. However, studies on international branding of services are rare. Research is also necessary on the characteristics of services offerings. For example, what are the roles of intangibility, inseparability, perishability, and heterogeneity in international services marketing? Virtually no research has investigated the pricing of services internationally. For services that can be offered online, differentiating prices cross-nationally likely poses key challenges. Work also remains in addressing the international distribution of services. For example, how does delivery of international services vary across online and brick-and-mortar channels?
Dimensions of international service encounters also merit substantial research (box 4 in Figure 1). Although scholars have investigated consumer behaviors or perceptions in cross-cultural services exchange, in international settings, research on service design and development, service delivery systems, service providers, servicescapes, and the nature and perceptions of business service buyers is lacking.
Regarding services internationalization (box 5 in Figure 1), scholars have investigated international market entry, including exporting, global sourcing, licensing and franchising, collaborative arrangements, and FDI. However, additional research is necessary on the performance dimension of international services (box 6), including issues frequently studied in the general services literature, such as value creation, purchase intentions, satisfaction, customer loyalty, and profitability, as well as the measurement of international performance. Performance has been identified as one of the most central variables in (international) marketing research, though with a lack of appropriate conceptualizations and operationalizations of the performance construct (Katsikeas et al., 2016). Research on competitive and strategic factors that drive international performance would be fruitful.

Contextual domain
There remains much potential for research on the external environment of services exchange (box 7 in Figure 1). Many scholars have explored the political, institutional, technological, and cultural environments that confront services providers. Literature is also considerable on technological issues, such as technology acceptance and adoption of services abroad. Scholars have explored services marketing in diverse cultures and cultural environments. However, rich opportunities remain to investigate the effects of government intervention, trade barriers, institutional environments, and legal and regulatory environments.
The global megatrend of digitization has brought severe shifts as a macrotrend in general, and it has affected the marketing discipline through social media, for example. Thus far, extant literature considers the role of technology in international services, such as information technology, the Internet, and e-commerce, but work remains in this area. Big data has been identified as one of the most relevant avenues for future research (Kunz et al., 2017). The increased availability of data creates new opportunities for relationship marketing and customer relationship management as well as for marketing research through, for example, social media monitoring. Other relevant topics include the digital service space, self-service technologies (e.g. Barua et al., 2018), consumer engagement in social media (Kesgin & Murthy, 2019), and new services of the sharing economy such as Uber or Airbnb. Technology adoption in an emerging market context is another area that offers promising opportunities for future research (Mishra et al., 2018). Although international communication and advertising based on traditional instruments have been widely investigated, additional research on social media and its interactive nature is necessary (e.g. online reputation management to cope with negative electronic word of mouth spreading globally in service failures).
In addition to digitization, sustainability is another macrotrend affecting business activities and, thus, the international marketing of services. Green marketing refers to a company's holistic orientation toward the environment and aims to reduce the impact of the firm on the environment (Papadas et al., 2017). Green organizational culture and green innovation also need more research attention (Gürlek & Tuna, 2018). Despite its relevance for a sustainable business strategy, an integrative framework of the green marketing concept is absent, and research is still in its infancy (Papadas et al., 2017). This applies particularly to the context of international services. While CSR research has been increasing in the international business literature (Zhao et al., 2018), only limited works on CSR in the context of service provision are available (Bolton & Mattila, 2015). Given its high relevance in both academia and business practice, CSR offers significant opportunities for future research (Zhao et al., 2018).
Cross-national variation in cultures, economic conditions, and institutional environments affects the efficient and effective provision of services. Emerging markets represent an exciting venue for future research, to examine both services marketing within these regions and international services marketing by firms based in emerging markets (e.g. Jain et al., 2019). For example, buyers in poor countries often have limited experience with high-technology channels for receiving services. Lower-income levels and weak infrastructure can affect pricing, communications, distribution, and packaging. Technology adoption among consumers in an emerging market context is an area that offers promising opportunities for future research (Mishra et al., 2018).

Methodological domain
In the methodological domain, research is required to better define and standardize units and levels of analyses. Scholars should strive for greater rigor in construct and scale development and the operationalization and validation of constructs. They should also aim to develop appropriate operational measures of concepts and phenomena and ensure that constructs and measures possess adequate face, construct, and external validity. Moreover, research should aim to develop models and theories with substantial reliability and validity across the range of national settings. Because foreign markets are characterized by diversity in language and culture, scholars will need to emphasize equivalency of conceptualizations and measures, as well as external validity. Scholars need to validate the quality of construct measurement in cross-national studies because instrument perceptions usually differ among diverse cultures and language groups. Greater rigor also is required in defining performance constructs and in the formulation and operationalization of relatively intangible constructs, such as inter-organizational relationships, service quality, and servicescapes. Finally, future research should employ a broader range of methodological approaches, such as experimental design, secondary data, or fuzzy-set qualitative comparative analysis.

Conclusion
Rooted in the fields of marketing and international business, two of the most dynamic fields in business research, the field of international services marketing is complex and ever-changing. Research in this area has not kept pace with the growing salience of services in global commerce and economic progress, as the relatively scant scholarship in the field attests. This article presents findings on extant literature in international services marketing from 1999 to 2018. Consistent with the early stages of research, we call for further scholarly research in this important area. Research in international services marketing can be disseminated in various ways. Gatekeepers in marketing and international business (i.e. leading scholars, editors, and reviewers) might promote future, substantive research. To do so, they can propose special journal issues on international services marketing. Conferences and colloquia are also potential vehicles for generating interest in the field. Doctorate-granting institutions should encourage young scholars to pursue related research topics.
This study has several limitations. First, although we included 41 academic journals in the search, we might have missed research published in other outlets. Second, we addressed multiple variables but did not provide additional findings and analyses to further clarify the state of research or offer epistemological assessments of foundations and developments. Third, the publication of research is ultimately determined by editors and editorial review boards. Future research might investigate how key actors shape patterns of publication on international services marketing. Finally, the study aimed mainly to support the research efforts of academic scholars. Future research might investigate the relevance and impact of extant literature for practitioners, the ultimate beneficiaries of knowledge from academic research.
If international services marketing is to become a viable field, scholars will need to expend greater efforts to develop models, theories, and frameworks that represent a cohesive, major stream of scholarly work. This article aimed to establish a baseline for research on international services marketing. We encourage scholars to focus their research accordingly.