Emotional Labor Strategies from Customer Point of View: A Systematic Literature Review

The behavior displayed by service employees affects customers’ perception of service quality and their level of satisfaction. Therefore, understanding emotional labor strategies has become a key competitive advantage for service organizations. The purpose of this study is to provide an in-depth review studies that discussed and examined emotional labor strategies from customer point of view. This study used a systematic literature review approach on emotional labor studies. The results showed that customer satisfaction, customer loyalty and word of mouth are considered the most important outcomes of emotional labor strategies. Further, the results showed that the majority of previous studies used dyadic questionnaire as a data collection method. More importantly, drawn from the review results, a research framework was developed to show the customer outcomes of emotional labor strategies and the mediators/moderators between emotional labor strategies and customer outcomes. This article is one of the earliest studies that provides a systematic review of previous studies on emotional labor from customer point of view and uncovers the definitions, models, and methods and factors in order to clarify the emotional labor concept.

This paper is organized as follows: 1-Presenting the review method of studies on EL from customer point of view. 2-Reporting the SLR results and conducting a detailed discussion of the development of the research framework. 3-Discussing the implications of the SLR. 4-Concluding the SLR results and discussing opportunities for future work.

Methodology
This study follows the guidelines of Bandara et al., (2011) by employing a four-phase method to extract, codify, analyze and interpret the existing EL studies from customer point of view. These phases include articles extraction, pre-analysis, actual coding and the results. The following sub-sections clarify each stage. This study aims to answer the following questions: 1-What are the conceptualizations of EL concept and strategies? 2-What are the outcomes of EL strategies factors in the previous research? 3-What are the mediators/mediators that have been used in previous research? 4-What are the data collection methods and the EL scales that prior studies used to examine the relationship between EL and customer outcomes?

Identification and Extraction of Studies
The first phase was identifying and selecting the primary studies from several online databases that are used to cover a wide range of publications by following Webster and Watson (2002) recommendations of not limiting the search process to a specific set of journals. The duration of selected studies extends from 2009 to 2018. The databases used were Scopus and Science Direct. These databases are relevant and provide reliable studies. Further, this paper includes additional relevant articles by applying a manual recursive search. A thorough search of the grey literature (e.g. Google) was also undertaken. The studies were extracted using keywords related to the research questions of this review such as: emotional labor and customer satisfaction, surface acting and customer satisfaction, deep acting and customer satisfaction, emotional labor and customer loyalty, surface acting and customer loyalty, deep acting and customer loyalty, emotional labor and word-of-mouth, etc. To ensure high level of accuracy and reliability of the results, the advanced search tool was applied. A total of 156 studies related to EL were identified. After removing the duplicated studies using Mendeley software, a total of 97 studies remained. Afterwards, inclusion/exclusion criteria were applied. Table 1 clarifies the inclusion and exclusion criteria were used in this study. Not in the selected period Not in Journals Non English EL from service employees point of view The respondents were service employees Non-empirical studies After applying the inclusion and exclusion criteria, a total of (14) studies remained. Figure 1 clarifies the distribution of the studies through the years. As can be seen the graph, the publication of emotional labor from customer point of view context have increased from 2009 to 2013. The highest number of publication was recorded in 2013 with 3 studies. In 2015 and 2016 the number of studies published was 2 in each year. In 2016, only 1study was published. This distribution shows how the interest of customer behavior in e-commerce has increased by years.

Preparing for Analysis
The pre-analysis phase consists of multiple steps. First, using Mendeley Desktop 1.19.2 in building a database references for all the primary studies. Second, converting all the primary studies to PDF files. After that, developing a file using Microsoft Word for each article to write all the information needed for the nodes. The suggested nodes were; EL conceptualization (EL definition and EL strategies), outcomes of EL strategies, mediators/mediators in previous models, and methodology used in previous research (Data collection method and EL scales). Finally, adding these files to Nvivo 12 in order to answer the SLR questions.

Actual Coding and Write-Up
As mentioned before, the first step was uploading all the Microsoft Word files on Nvivo 12. Then, creating a new file inside the list of files. After that, using two different layouts (the first one for the questions and the second one for the answers). Finally, applying the auto coding technique in order to design the nodes (EL conceptualization, EL outcomes, Mediators/Moderators, data collection methods and EL scales).

Results
This section presents detailed answers of the SLR questions for this review. The first section discusses how previous studies conceptualized the term El and presents the main definitions of EL strategies. The second section discusses the factors of EL including customer outcomes of EL and mediators/moderators that have been used in previous studies. The final section provides the data collection methods and the EL scales that the previous studies used to examine EL strategies. Hochschild (1983) is considered the first researcher who introduced emotional labor concept in her book The Managed Heart: Commercialization of Human Feeling. According to Khan and Awan (2018), the main idea of her book is that service organizations require their employees to sell their time and effort as well as regulate their emotions at work while dealing with customers in order to maximize the their profits.

Conceptualizing Emotional Labor
Hochschild (1983) stated that emotional labor is the situation in which service employees have to regulate their emotions in order to meet organizational display rules. She clarified that emotional labor takes place only if three things occur as follows: 1) There is a face-to-face or aural contact between employee and other person or customer.
2) The employee produces an emotional response in other person or customer.
3) There is a control on all emotional activities of the employees from the employer.
In the same context, Grandey (2000) defined emotional labor as the process of managing both feelings and expressions to reach the organization's goal. Emotional labor became one of the most important topics in service industry, which led many researchers to define it such as (Goldberg & Grandey, 2007;Grandey, 2000;Grove et al., 1998;Hochschild, 1983;Van Dijk et al., 2011). Based on the reviewed articles, we summarized all the definitions of EL that have been used in primary studies as shown in Table 2:  Table 2

. Emotional labor definitions EL Definition
Originated from It's the situation in which service employees have to regulate their emotions in order to meet organizational display rules. (Hochschild, 1983) The kind of impression management that helps an individual to direct his/her behavior.
( Grove et al., 1998) The process of regulating emotion by means of either antecedent-focused emotion regulation or response-focused emotion regulation. (Gross, 1998a;1998b) The process of managing both feelings and expressions of service employee to reach the organization's goal. (Grandey, 2000) The management of emotional display by staff to satisfy organizational exceptions during voice-to-voice of face-to-face interpersonal interactions. (Van Dijk et al., 2007)

Emotional Labor Strategies
According to Hochschild (1983), emotional labor concept consists of two different strategies to manage and control service employee's emotions. Surface acting strategy defined as showing fake emotions to customers. On the other hand, deep acting strategy defined as making an effort to feel specific emotions according to conditions found in. After ten years of Hochschild's (1983) book, Ashforth and Humphrey (1993) suggested a third emotional labor strategy called genuine acting strategy. They argued that some emotions could be truly felt without any effort from service employees in displaying it to customers. The majority of researchers didn't accept the true feelings strategy except (Ashforth & Humphrey, 1993;Diefendorff et al., 2005;Lee et al., 2014;Karim & Weisz, 2011;Sharpe, 2005;Venkatesh & Balaji, 2013;Yuhanis & Zaiton, 2010). Therefore, this SLR concentrates only on surface acting (SA) and deep acting (DA) strategies. Based on the reviewed articles, we summarized all the definitions of (SA) and (DA) strategies that have been used in primary studies as shown in Table 3 and 4:  Table 3. Surface acting strategy definitions SA Definition Originated from Faking emotions by displaying emotions not actually felt.
(Hochschild, 1983) Managing one's feeling as a result of observable expressions. (Bitner, 1990;Bowen, 1990) The process of faking or outwardly assuming the desired emotions.
(Ashforth & Humphrey, 1993) The process of regulating the displayed emotions without changing the inner feelings. (Gross, 1998a) Modifying the behaviors of service employees by suppressing or faking expressions and displaying emotions not actually felt.

(Grandey, 2000)
Putting on a mask without truly change the inner feeling and performance. (Grandey, 2003) The process of striving to customize the apparent gestures of actions without altering the inner feelings. (Zammuner & Galli, 2005) Manipulating outward appearances (facial expressions, gestures and voice tone) in situations that demand an emotional display that is contrary to the felt emotions.  Originated from It's an internal transformation and an active effort to feel more positively during customer-service interactions. (Hochschild, 1983) It's the management process of the actual feeling. (Bitner, 1990;Bowen, 1990) The process of modifying inner feelings to meet the desired emotions.
(Ashforth & Humphrey, 1993) It's a strategy of modifying the behaviors of service employees through internal change in order to display genuine emotions. (Gross, 1998a) Managing experienced emotions to be same as, or as close as possible to, the required emotions of a certain situation. (Grandey, 2003) The process of striving to regulate the inner feelings to match the expression of emotions that the service employee is obligated to show. (Zammuner & Galli, 2005) It's a strategy of attempting to modify actual felt emotions so that a genuine emotional display follows. (Groth et al., 2009)

Outcomes of Emotional Labor Strategies
Through the SLR, we are further able to identify and provide a comprehensive picture of customer outcomes of emotional labor strategies. The majority of primary studies considered customer satisfaction, word of mouth and customer loyalty as the outcomes of emotional labor strategies. Customer satisfaction defined as customer's feeling of pleasure, which results from the comparison process between a product / service perceived performances and customer's expectations (Kotler & Keller, 2009). Further, it represents how customers evaluate a product or service after consumption (Mittal & Carly, 2010). From a total of 14 studies, 7 studies considered customer satisfaction/service satisfaction as one of customer outcomes of emotional labor strategies (Hur et al., 2015;Lee et al., 2014;Medler-Liraz & Yagil, 2013;Wang & Groth, 2014;Wu & Shen, 2013;Wu & Yuan, 2012;Yagil, 2012).
Regarding to word of mouth (WOM), it can be defined as a form of informal communication between two people or more about the ownership and characteristics of specific product or service (Chan & Ngai, 2011;Taylor et al., 2012). Through the SLR, we noticed that 5 studies of our primary studies suggested word of mouth as one of customer outcomes of emotional labor strategies (Aziz et al., 2016;Chi & Chen, 2018;Khan & Awan, 2018;Lee et al., 2014;Van Dijk et al., 2011).
According to Akbar and Parvez (2009), customer loyalty represents customer attitude and commitment of repurchasing a specific product or service. Customer loyalty occurs when customers have a kind of preference to purchase a specific product or service consistently from a particular provider for a period of time (Lovelock & Wirtz, 2011). We noticed that 4 studies from the 14 primary studies proposed customer loyalty as one of customer outcomes of emotional labor strategies (Groth et al., 2009;Khan & Awan, 2018;Medler-Liraz & Yagil, 2013;Yagil, 2012).
The primary studies of SLR proposed other outcomes as customer outcomes of emotional labor strategies such as service quality, customer-employee rapport and purchase decision. Table 5 summarizes the outcomes of emotional labor strategies that have been used in our primary studies as follows:

Mediators/Moderators
This section provides a comprehensive picture of all the mediators and mediators that previous studies used in EL literature from customer point of view.
Out of 14 studies, 7 studies used different mediators including (customer satisfaction, customer loyalty, hostile Behavior by service employee, job satisfaction, customer emotional experience, employee burnout and work engagement). Table 6 presents these mediators, clarifies the mediating relation and indicates to the study that used this mediator as follows: Customer emotional experience mediates the relationship between emotional labor strategies (Surface acting and deep acting) and purchase decision (Tang et al., 2013) Employee Burnout Employee burnout mediates the relationship between emotional labor strategies (Surface acting and deep acting) with customer satisfaction and customer loyalty (Yagil, 2012)

Work Engagement
Work engagement mediates the relationship between emotional labor strategies (Surface acting and deep acting) with customer satisfaction and customer loyalty (Yagil, 2012) On the other hand, only 4 studies used moderator variables including (Relationship strength, service personalization, customer mood, customer deep acting detection accuracy, customer surface acting detection accuracy, service type and service sweet hearting). Table 7 presents these moderators, clarifies the moderating relation and indicates to the study that used this moderator as follows: Table 7. Moderators

Relationship Strength
Relationship strength between service employee and customers moderates the relationship between emotional labor strategies (Surface acting and deep acting) and customer satisfaction (Chi & Chen, 2018). Relationship strength moderates the negative relationship among employee faked positive emotions, employee suppressed negative emotions and customer satisfaction (Wang & Groth, 2014). Service Personalization Service personalization moderates the negative relationship among employee faked positive emotions, employee suppressed negative emotions and customer satisfaction (Wang & Groth, 2014).

Customer Mood
Customer mood moderates the relationship between emotional labor strategies (Surface acting and deep acting) and customer satisfaction, between customer satisfaction and customer loyalty and also between customer satisfaction and word of mouth (Khan & Awan, 2018). Customer Deep Acting Detection Accuracy Customer deep acting detection accuracy moderates the relationship between deep acting strategy and perceived customer orientation and also between deep acting strategy and perceived service quality (Groth et al., 2009). Customer Surface Acting Detection Accuracy Customer surface acting detection accuracy moderates the relationship between surface acting strategy with perceived customer orientation and perceived service quality (Groth et al., 2009). Service Type Service type moderates the relationship between surface acting strategy with perceived customer orientation and perceived service quality (Groth et al., 2009) Service type moderates the relationship between deep acting strategy with perceived customer orientation and perceived service quality (Groth et al., 2009). Service Sweet Hearting Service sweet hearting moderates the relationship between emotional labor strategies (Surface acting and deep acting) and customer satisfaction (Chi & Chen, 2018).

Data Collection Methods and EL scales
This section presents the SLR results regarding data collection method that previous studies used to collect their data, the industries where the data collected and the scales that used to examine emotional labor strategies.
Regarding to the industries where the data collected, SLR results revealed that the primary studies collected data from different industries such as airline industry, mobile phone shop sites, insurance companies and homecare firms. Further, SLR results showed that there are multiple scales have been used in the primary studies in order to examine emotional labor strategies as shown in Table 8:  (Wu & Shen, 2013) Questionnaire Hotel in China Not specified (Wu & Yuan, 2012) Dyadic questionnaire Transportation in China Not specified (Yagil, 2012) Dyadic questionnaire Variety of service industries in Israel (Brotherdige & Lee, 2003)

The Proposed Conceptual Framework
After reviewing the previous frameworks of all the primary studies, we noticed that the majority of studies examined emotional labor strategies from both point of views (service employees and customers). Out of 14 studies, there are only four studies that gave the full concentration on examining the effect of emotional labor strategies on customers without examining their effect on service employees (Aziz et al., 2016;Khan & Awan, 2018;Lee et al., 2014;Wu & Shen, 2013). Therefore, the proposed conceptual framework of this study concentrates only on emotional labor strategies from customer point of view. Also, SLR results revealed that only one study considered genuine acting strategy as one of emotional labor strategies and examined its relationship with customer outcomes (Lee et al., 2014). Therefore, the proposed conceptual framework of this study considers genuine acting strategy as one of emotional labor strategies.
The proposed conceptual framework of this study depends on two studies (Khan & Awan, 2018;Lee et al., 2014). According to Khan et al. (2018) framework, the independent variables are surface acting strategy and deep acting strategy. They are hypothesized to have direct relationship with customer satisfaction and indirect relationship with customer loyalty and word of mouth. Meanwhile, customer satisfaction is hypothesized to mediate the linkage between independent variables with customer loyalty and word of mouth. Customer mood is hypothesized to moderate the linkage between emotional labor strategies and customer satisfaction and also between customer satisfaction and dependent variables (customer loyalty and word of mouth). Dependent variables are labeled as customer loyalty and word of mouth. On the other hand, Lee et al. (2014) framework consists of three independent variables (Surface acting strategy, deep acting strategy and genuine acting strategy), while dependent variables are labeled as customer satisfaction and word of mouth.
The independent variables of the proposed conceptual framework of this study are surface acting strategy, deep acting strategy and genuine acting strategy. Meanwhile, customer satisfaction is hypothesized to mediate the linkage between independent variables with customer loyalty and word of mouth. Customer mood is hypothesized to moderate the linkage between independent variables with customer satisfaction. Also it proposes to moderate the relationship between customer satisfaction and dependent variables (customer loyalty and word of mouth). Dependent variables are labeled as customer loyalty and word of mouth as shown in Figure 2: Figure 2. The Proposed Conceptual Framework

Discussion and Implications
The purpose of this study is to conduct a systematic literature review on emotional labor from customer point of view. This article focuses on empirical research studies that examined customer outcomes of emotional labor strategies. A total of 14 studies were identified through our systematic review from prominent academic databases. More importantly, this paper proposes a research framework to expose the mediators/moderators and outcomes of emotional labor strategies from customer point of view. This study is one of the earliest studies that present the outcomes of emotional labor strategies and mediators/mediators that have been used in previous studies. The results showed that customer satisfaction, customer loyalty and word of mouth are considered the most important outcomes of emotional labor strategies. In addition, the results proved that customer satisfaction is considered as a mediator between emotional labor strategies with customer loyalty and word of mouth (Chi & Chen, 2018;Khan & Awan, 2018). On the other hand, the results showed that customer mood partially moderates the relationship between emotional labor strategies with customer satisfaction and also between customer satisfaction with customer loyalty and word of mouth (Khan & Awan, 2018).
This study revealed that previous studies on emotional labor strategies from customer point of view used both methods self-administrated questionnaire and dyadic questionnaire for data collection process. Further, it reveals that the majority of previous studies used the emotional labor scale that developed by Brotherdige and Lee (2003) to examine emotional labor strategies.

Conclusion
This study provides a systematic review of emotional labor from customer point of view. The current study derives insights based on the discussion of emotional labor conceptualization, outcomes, mediators, moderators, data