Firm policies and employees’ participation in conversation about their employer on social media

This paper studies the relationship between firms’ strategy and policies in regard to social media and their employees’ propensity to endorse them by using their personal social media accounts. In particular, the study investigates the effect of employees’ perception of firms’ social media strategy and initiatives aimed at influencing employees’ behavior on their personal social media profiles (communication of policies on the use of social media, training programs, and encouragement to join social media conversations regarding the firm). Based on the responses of 224 employees who use their personal accounts to talk about their firms, findings show that employees’ positive evaluation of firms’ social media strategy and firms’ explicit encouragement are positively associated with employees’ propensity to endorse their firms on social media. Moreover, results reveal the moderating effect of employees’ frequency of social media use on the relationship between communication of social media policies and the employees’ propensity to endorse their firm, as well as on the relationship between training programs and the propensity to endorse. This study provides evidence of the influence of firms’ social media activity and policies on the willingness of employees to promote and advocate their employers using their personal accounts, with theoretical and practical implications. The research also suggests that the effectiveness of firms’ policies may differ according to the frequency of social media usage by employees.


Introduction
Social media enable users to create several forms of media content-i.e., user-generated content-that are shared with peers through multiple platforms. At the same time, firms understand that social media could play a significant role in building their brands among stakeholders and are trying to fully exploit their potentiality to achieve better results.
Social media allow firms to share information, keep stakeholders updated, identify their interests, and interact with them in real time, shortening the response time needed to respond to their inquiries (Kluemper et al., 2016), and to enhance their perception about the firms and their brands. Firms adopt social media policies aimed not only at favoring brand building and customer engagement, but also at increasing employees' engagement, because they can act as brand ambassador in the digital environment, amplifying their firms' messages and promoting firms' products, services, and reputation (Walden, 2018).
Employees interact with their peers through social media for personal and workrelated reasons (Sakka & Ahammad, 2020) and their usage of these platforms could be perceived either as an opportunity-given they are well informed about firms' goals and strategies-or as a risk, because employees could, voluntarily or involuntarily, cause damage to their firms (Mazzei & Butera, 2016;Rokka et al., 2014). In the former perspective, employees use social media to communicate valuable and reliable information about their firms, promoting a positive perception of the firm among external stakeholders and positively affecting firm reputation (Dreher, 2014). In the latter, employees could express negative sentiment or post inappropriate statements that could result in negative outcomes for the firms they are working for (Sakka & Ahammad, 2020).
To avoid the undesirable outcomes that could derive from damaging social media behavior, in some cases, firms limit employees' participation in online conversation on the firm. However, because consumers and other peers perceive employees' voice on social media as useful and trustworthy (Morokane et al., 2016), in many other cases, firms attempt to define solutions to strategically manage employees' behavior on social media (Dreher, 2014).
Previous studies have highlighted the role employees play in brand-building, given their opportunity to convey brand values during their social media conversations with firm stakeholders (Gremler & Gwinner, 2008;Henkel et al., 2007;Jo Hatch & Schultz, 2003;Labrecque et al., 2011;Punjaisri et al., 2009;Rokka et al., 2014;Sirianni et al., 2013;Vallaster & de Chernatony, 2006). Yet, efforts are needed to better understand the contribution employees could make by endorsing their firm on social media, and how firms can promote this endorsement. In fact, despite several studies investigating consumer brand engagement (Trunfio & Rossi, 2021) and regardless of the importance of social media to employees and firms, there is a lack of research focused on employee brand engagement on social media and the possible benefits firms could derive (Goldring et al., 2022). In fact, beyond the reasonable assumption that employees' endorsement can be beneficial to the firm, little is known about how firms attempt to manage employees' behavior on social media in order to avoid risks and/or exploit potentialities associated with their participation in the online conversation about the firm and its products/services (Morokane et al., 2016), and the efficacy of these efforts.
Therefore, this study tries to fill this gap by investigating the relationship between firms' social media strategy and policy and the propensity of their employees to endorse the firm via social media.
Moreover, being based on a questionnaire survey of employees, the present work also answers the call for studies that collect the voice of employees (Mazzei & Butera, 2016). More precisely, we identified a sample of employees that declared they use their social media profiles to talk about the firm, in order to deepen the understanding of factors that can influence how these employees talk about the firm.
The study makes a contribution to extant literature by providing a deeper understanding of how firms may try to manage employees' social media behavior by implementing social media policies and practices that could support employees in better understanding how to conduct themselves appropriately in the social media environment. In detail, the study sheds some light on the relationship between firms' social media policies and employees' use of their personal accounts to endorse their firms. First, the study shows that employees' positive evaluation of the firm's communication strategy is associated with higher propensity to endorse the firm on social media. Second, findings reveal that by encouraging employees to join online conversation about the firm, firms may enhance their positive perception on social media. Third, the study sheds some light on the moderating role of the frequency of social media use by employees. In this regard, the study suggests that the effects of both internal communication of social media policy and of training programs on employee's propensity to endorse the firm are more beneficial when considering employees who use their social media profiles less frequently.

The use of social media by employees
The literature has studied employees' use of social media from different perspectives. Previous studies have highlighted that employees could use their personal social media not only to share firm-related content and express their ideas and opinions about their employers/firms with their family members, friends, and peers for personal reasons, but also to participate in discussions related to work. Firms are increasingly using social media as a formal communication tool, also enabling employees to develop contacts with colleagues and create and share content with multiple communities (Sakka & Ahammad, 2020). Social media usage for professional purposes has been proven to have several significant implications, such as for corporate reputation (Etter et al., 2019), employee engagement (Goldring et al., 2022), and talent acquisition (Korzynski et al., 2020). The extant literature has also revealed that employees can potentially use social media at work to collaborate and exchange information with colleagues and to communicate internally (Song et al., 2019). In this context, it is still partially unclear whether the use of social media by employees has positive or negative implications for firms and brands. On one hand, some authors have high-lighted that negative outcomes could derive from inappropriate or detrimental usage of employees' personal social media accounts (Miles & Mangold, 2014); on the other hand, other researchers have found evidence of the positive contribution employees could make to their firms' performance outcomes by supporting them in the social media environment, suggesting that employees could be engaged as advocators to promote firms' products and brands (Dreher, 2014;Kang & Sung, 2017;Lee, 2021).
In regard to negative effects, it has emerged that employees choose to make their voices heard through social media especially when they do not perceive they are being heard internally, or when they believe reprisal is a probable outcome (Miles & Mangold, 2014). In these cases, employees express damaging opinions and feelings on social media about the firm they are working for because they feel they can control the discussion and receive support from other peers (Lee & Kim, 2021). Moreover, it has emerged that the use of social media by employees is perceived as negative by several firms that are concerned about employees' social media surfing and posting at work. Believing that social media could represent a distraction for employees while they are performing their assigned task, many managers have decided to completely block firm devices to deny social media access (Bizzi, 2018). Even if in today's highly connected world, employees' social media behaviours cannot be totally under employers control, firms are increasingly willing to monitor and manage their employees' voice to ensure that their posting activities are aligned with firm social media strategies and values (Smith et al., 2021). Some authors have also pointed out that employees not knowing how to safely and appropriately use social media feel fear and anxiety when their employers ask them to proactively use these media to promote the firm, leading to negative feelings (Brooks, 2015).
In regard to positive effects, employees' willingness to promote firm-related messages and advocate arises when employees perceive themselves as part of the firm. In fact, previous studies have highlighted that when employees are motivated, satisfied, or committed, and when they perceive that their firm is making an effort to provide employee benefits unconditionally, they are also likely to exhibit higher performance, to trust the firm, and to enhance the firm's public image and reputation (Lee, 2021;Miles & Mangold, 2014). Information created and distributed by employees in the social media environment can thus be beneficial not only for the firm but also for external audiences, because their positive word of mouth (WOM) not only suggests their engagement but could also affect stakeholder perception about the firm and its reputation among them (Kang & Sung, 2017;Lee, 2021). From this perspective, employee advocacy is related to both positive WOM and employees' willingness to defend their firm when it is criticized in the external environment (Walden & Kingsley Westerman, 2018). Thus, firms are now increasingly interested in encouraging employees to share positive content expressing advocative posts or applauding their firms' management (Krishna & Kim, 2015). Additionally, this positive attitude toward the firm in the social media scenario is also encouraged by employers because they perceive them as important sources of competitive advantage (Dreher, 2014;van Zoonen et al., 2014). Previous studies suggest that internal endorsers could deliver to stakeholders messages considered direct and trust-inspiring and, with specific regard to employees, it has also been shown that involving them as spokespeople can effectively contribute to increasing consumers' perception about the honesty and trans-parency of firms' communication (Fleck et al., 2014). Hence, managers are aware of the importance of managing employees' supportive behaviours on social media (Walden, 2018) because their voices represent an instrument that has the potential to amplify the impact of positive messages and improve corporate reputation (Lee & Kim, 2021).

Perception of social media strategy and employees' propensity to endorse their firms on social media
Given the potential benefits associated with employees' advocacy, scholars have started investigating factors influencing employees' propensity to endorse the firm, as well as policies that firms can adopt to elicit support of employees on social media and induce their active role in brand co-creation (e.g., Dreher 2014; Goldring et al., 2022;Walsh et al., 2020). Endorsing the firm on social media is a form of brand citizenship behavior, that is, an individual voluntary behavior in favor of the brand of the organization, which is outside of role expectations (Burmann & Zeplin, 2005). Previous literature has highlighted that the employee-organization relationship plays a central role in explaining brand citizenship behaviors, including endorsement on social media (Lee & Kim, 2021). This relationship is influenced by several factors, and firms may try to enhance it through their overall human resource policies and internal corporate social responsibility practices (Lee & Kim, 2021;Saleem & Hawkins, 2021). In this study, we focus on policies concerning social media and the potential role they can play in enhancing employees' propensity to endorse their firms. From this perspective, it is possible to hypothesize the relevance of both the firm social media strategy (and how it is perceived and evaluated by the firm employees), and the policies aimed at favouring firms' endorsement by employees.
In regard to firm social media strategy, its positive evaluation by employees may contribute to creating a positive relationship between the firm and its employees, which, in turn, favours their propensity to endorse the firm. First, transparent and fair communication contributes to generating relational satisfaction and trust-factors that can foster employees' social media engagement and their orientation to share positive information about their organization (Goldring et al., 2022;Wang, 2020). Second, brand citizenship behaviours, such as endorsing the firm on social media, require congruity between the brand and employees' identity (Saleem & Hawkins, 2021). Employees are motivated to explicitly support the firm and its brand if they perceive a fit with their own identity and if they experience brand pride-that is, "the pleasure taken in being associated with the (corporate) brand" (Helm et al., 2016, p. 62). A positive evaluation of the firm social media strategy by employees may contribute to enhancing this perceived fit and brand pride, increasing the positive emotions associated with the sharing of favourable organizational content (Lee & Kim, 2021). Therefore, we expect that employees who appreciate the social media strategy of their firms are more likely to endorse them on social media.

H1
Employees' positive evaluation of their firms' social media strategy is positively related to their propensity to endorse the firm.

Internal communication of policies on the use of social media and employees' propensity to endorse their firms
As previously highlighted, the role played by employees on social media, as well as their consequent contribution to the reputation of the organization, is inevitable (Etter et al., 2019;Rokka et al., 2014). Being aware of the importance of the potential role played by employees in presenting their brands to the stakeholders, firms are continuously seeking to understand how they can leverage potential benefits associated with the participation of employees in online conversations about the firm and its brands. Previous studies underline how important it is for firms to promote various initiatives to induce employees to endorse them on their social media profiles, and to ensure that employees understand how they can effectively support the firm on the internet (Dreher, 2014). Saleem and Hawkins (2021) have shown that employee-created social media content affects customers' perceptions, which, in turn, influence customers' behaviors in terms of both increased purchase intention and WOM. Customers perceive employees as credible due to their expertise and direct knowledge of the firm and its products (Saleem & Hawkins, 2021). At the same time, they perceive employeecreated content as a form of brand citizenship behavior that transcends what is strictly required of the employees (Burmann & Zeplin, 2005;Podsakoff et al., 2000). These perceptions concerning employee-created social media content are associated with positive customers behaviors, suggesting that employees, by using their own social media accounts, can be part of a process of brand co-creation. It is thus important for firms to develop internal branding tools and employee ambassador programs aimed at encouraging and supporting employees to create brand-related content and act as brand ambassadors (Schmidt & Baumgarth, 2018). Internal branding, in fact, consists of "a strategy to promote the brand within the organization to ensure that employees adequately deliver the brand promise to external customers" (Barros-Arrieta & García-Cali, 2021, p. 136).
Studies on internal branding tools show the relevance of internal communication, which influences brand knowledge, attitude, and behaviours (Iglesias & Saleem, 2015) (Punjaisri & Wilson, 2007). In particular, we propose that an adequate communication of policies on the use of social media may favor employees' propensity to endorse the firm through these media. Clearly defining and communicating the firm social media policy to employees may stimulate workers to join the social media conversation about the firm (O'Connor et al., 2016), by allowing them to be aware of which activities they are allowed to perform on these media and to be informed about what kinds of content are considered appropriate.
Given that different firms may have different attitudes towards the participation of employees in online conversations (Rokka et al., 2014;Mazzei & Butera, 2016), it is important for employees to know that their firm allows them to use their own social media accounts to talk about the firm and appreciates their doing so. A well-defined set of rules helps employees understand what they can do (O'Connor et al., 2016) and, thus, may favor more active involvement of employees in conversations about the firm and its brands and products. In contrast, even employees with a positive relationship with the firm may be reluctant to use their social media profiles to endorse the firm if they do not have a clear understanding of what kind of use of social media is permitted, appropriate, and considered desirable by the firm.
Finally, communication of the social media policy of the firm may also enhance employees' propensity to endorse the firm by helping them understand their potential role, given that they are motivated to engage in brand citizenship behaviors if they perceive that their contribution may have relevance (Burmann & Zeplin, 2005).
We thus argue that communicating to employees the policies concerning the use of social media may favor their propensity to endorse the firm on these media.
H2 Communication of policies on the use of social media is positively related to employees' propensity to endorse the firm.

Training programs on the use of social media and employees' propensity to endorse their firms
In order to have an impact, firm policies on the use of social media need not only to be known by employees, but also to be adequately understood. Training programs on social media may thus represent an important complement to internal communication of policies because they help workers understand the content of the policy, as well as how it concretely applies to everyday life (O'Connor et al., 2016). Hence, training may reinforce the communication of social media guidelines and policies by explaining rules and procedures, presenting risk and opportunities associated with social media use, as well as clarifying technical aspects and best practices (Dreher, 2014). Indeed, employees with few competencies on how social media work could have some difficulties in actively using these tools (Cervellon & Lirio, 2017). Firms, thus, by carrying out training programs-both on the basics of social media and on their social media policies-can enhance employees' skills and confidence with these media and, as a consequence, increase employees' willingness to talk about their firm on their personal social media profiles (Cervellon & Lirio, 2017;O'Connor et al., 2016).
Even extant literature that has suggested the need to develop programs intended to facilitate employee-generated content highlights the importance of training initiatives aimed at increasing employees' knowledge and skills, also with specific regard to online content creation (Saleem & Hawkins, 2021).
Other studies have explicitly investigated how the level of social media competencies of employees may affect the role they play in the online conversation. Walsh et al. (2016) have developed a scale to measure employees' company reputation-related social media competencies, which has been subsequently modified and assessed using data on three culturally distinct countries (Germany, China, and the United States) (Walsh et al., 2020). Using this scale, the authors found that the level of employees' competencies in relation to social media use is positively associated with positive WOM and negatively associated with bad-mouthing behavior. The main managerial implication of this result is that it is possible to promote employees' endorsement by providing training to employees in order to enhance their competencies concerning the use of social media, supporting, in particular, those characterized by the greatest competence deficiencies (Walsh et al., 2020).
In sum, we argue that employees involved in training initiatives concerning social media use tend to be more inclined to endorse the firm on these media.
H3 Training programs on the use of social media are positively related to employees' propensity to endorse the firm.

Encouraging employees to join social media conversation about the firm and employees' propensity to endorse the firm
As highlighted before, employees may be reluctant to join online conversations about their firm if they are unsure whether the firm judges this behavior as appropriate. This is a critical point given that different firms have differing perceptions and approaches concerning the role played by employees on social media (Mazzei & Butera, 2016;Rokka et al., 2014). From this perspective, it may be useful for firms not only to define and communicate policies that allow workers to use their social media accounts to talk about the firm, but also to explicitly encourage employees to join and contribute to social media conversations concerning their employers (Dreher, 2014).
Moreover, employees might not be aware that supporting their firm on social media could be useful for their employers and, consequently, they might not place any importance on this task. Extant literature has highlighted that employees are more likely to be motivated to engage in brand citizenship behaviors if they perceive that their potential role is not irrelevant and understand how they can contribute to the success of the brand (Burmann & Zeplin, 2005). In this regard, Piehler (2018) found that behaviour relevance (i.e., employees' understanding that they contribute, through their behaviour, to the brand's success) is positively related to brand citizenship behaviour, including brand endorsement. Firms can emphasize the relevance of the role played by employees by explicitly encouraging them to join online conversations about the firm.
Moreover, Lee and Kim (2021) found that enjoyment is one of the drivers of employees' advocacy intentions on their personal social media accounts. Indeed, hedonic motives turned out to be relevant in explaining the use of social media for work purposes (Leftheriotis & Giannakos, 2014), and some employees enjoy posting content concerning their firms and receive attention from the firm itself (Smith et al., 2017). Firms, by explicitly encouraging employees to endorse them on social media provide a sort of guarantee regarding the fact that employee-generated content is appreciated and considered a value-add. This, in turn, may favor positive emotions associated with endorsing the firm using personal accounts.
Hence, we expect that the explicit encouragement to use social media to talk about the firm may positively affect employees' propensity to endorse the firm on these media. Therefore, we propose the following hypothesis.
H4 Encouraging employees to join social media conversation about the firm is positively related to employees' propensity to endorse the firm.

Frequency of social media use and impact of firm policies aimed at favoring brand advocacy
Initiatives adopted by firms to influence employees' behavior on their personal social media profiles could generate different reactions by employees, depending on their characteristics and their social media approaches. In particular, in this study, we focus on the frequency of usage of social media, because this characteristic implies different knowledge, skills, and perceptions concerning the role played by social media, as well as attitudes toward their use; consequently, it may influence the impact of firms' initiatives aimed at enhancing employees' propensity to endorse the firm on social media (Archer-Brown et al., 2018).
Extant literature has highlighted the importance of assessing the level of social media-related competencies to identify employees who display the greatest competence deficiencies and provide training and support where needed (Walsh et al., 2020). Indeed, the need for support may differ significantly for different categories of employees (Cervellon & Lirio, 2017). The potential impact of training and internal communication concerning social media is higher in the case of employees that are not confident with these media and, thus, are not aware about what kinds of content may be appropriate and/or have not adequate technical skills. We expect that heavy social media users tend to have higher knowledge concerning social media, their technical aspects, and their mode of use, compared to individuals that utilize social media rarely (Archer-Brown et al., 2018). We thus assume that employees' frequency of social media use may influence the relationship between the communication of policies on the use of social media and employees' propensity to endorse the firm, as well as the relationship between training programs on the use of social media and employees' propensity to endorse the firm. In particular, we expect that the positive association between these initiatives (communication of social media policy and training) and the propensity to endorse the firm is stronger in presence of lower frequency of social media use.
We also expect that the relationship between the explicit encouragement to join social media conversation about the firm and employees' propensity to endorse the firm is mitigated in presence of higher frequency of social media use. Indeed, heavy social media users are more likely to be aware of the relevance of their potential role in contributing to the success of the brand; and this awareness promotes brand citizenship behavior, including brand endorsement (Burmann & Zeplin, 2005;Piehler, 2018). Consequently, they may have less need for explicit encouragement compared to individuals that use social media rarely. Moreover, as previously highlighted, hedonic motives may contribute to explaining the use of social media for work purposes and endorsing the employer (Goldring et al., 2022;Leftheriotis & Giannakos, 2014;Smith et al., 2017). Individuals that use social media frequently are more likely to enjoy a wide use of these media, and thus explicit encouragement might be less necessary in order to induce the gratification associated with endorsing the firm.
Hence, we propose the following hypotheses.
H5a Employees' frequency of social media use negatively moderates the relationship between communication of policies on the use of social media and employees' propensity to endorse the firm, such that communication of policies will have a stronger (weaker) influence on employee's propensity to endorse when the frequency of employees social media use is lower (higher).
H5b Employees' frequency of social media use negatively moderates the relationship between training programs on the use of social media and employees' propensity to endorse the firm, such that training programs will have a stronger (weaker) influence on employee's propensity to endorse when the frequency of employees social media use is lower (higher).
H5c Employees' frequency of social media use negatively moderates the relationship between encouraging employees to join social media conversation about the firm and employees' propensity to endorse the firm, such that encouraging employees to join social media conversation about the firm will have a stronger (weaker) influence on employee's propensity to endorse when the frequency of employees social media use is lower (higher).

Research methodology
To test the research hypotheses, the paper adopted a quantitative approach using a web-based questionnaire sent to a sample of employees recruited from a panel through a digital platform administered by IPSOS 1 . IPSOS manages some of the most extensive panels in the world (3.54 million members across 50 markets), and, in Italy, it has developed a panel of individuals that is balanced and in line with the Italian population's characteristics in terms of age, gender, and region of residence. The questionnaire asked the surveyed employees to self-report their answers on a 5-point Likert scale. Employees were required to answer questions about their use of personal social media accounts, their propensity to endorse their firms on social media, and their firms' activity and policies concerning these media.
The survey was carried out in Italy on a panel of 4,000 individuals, and 734 questionnaires were returned, accounting for an 18.4% response rate. Given that the aim of the study is to investigate the effect of firms' initiatives on the employees' propensity to endorse the firm, the respondents that reported not using personal social media profiles to talk about their firms were excluded, leading to a sample of 274 interviewees who stated that they use their personal social media accounts to talk about the firms they work for. Due to missing data, other 50 responses were excluded, leading to a final sample of 224 respondents. Table 1 summarizes the descriptive statistics of the sample's characteristics. In particular, data show that most of the interviewees are in the age group 25 to 44 years (51.8%) and the percentages of male (50.9%) and female (49.1%) respondents are almost equal. More than half of the respondents are office workers (56.3%); almost half of the interviewees have an upper secondary school education (47.8%), while the proportion of those with a lower education is very low (4.8%).
As shown in Table 2, the majority of the sample reported that they use Facebook to talk about their firms (85.3%), followed by Instagram (35.7%), and by LinkedIn and Twitter (26.8% and 25.4%, respectively). Finally, data collection reveals that a large majority of the sample uses social media every day (84.8%). To examine the impact of the independent variables on the dependent variable and the moderating role of the frequency of social media use by employees, we performed multiple regression analysis using IBM SPSS version 28.0. The multiple regression analysis was chosen for two reasons. First, our study is a first and an exploratory attempt to understand the effects of employees' perception of firms' social media strategy and of firms' initiatives on the employees' propensity to endorse their firms. Regression analysis has been suggested as a suitable and reliable method of identifying the relationship between each independent variable and the dependent variable when testing an exploratory conceptual model (Nunkoo & Ramkissoon, 2012). Second, this methodology is adequate in the presence of single-item independent variables such as those included in this study (Petrescu, 2013).
The dependent variable evaluates the propensity of employees to endorse their firms and was measured through a four-item scale adapted from Morokane et al. (2016). To test the hypotheses H1-H2-H3-H4, four explanatory variables were considered: employees' evaluation of their firms' social media strategy, communication of policies on the use of social media, training programs on the use of social media, and encouragement to join social media conversations regarding the firm. To test the hypotheses H5a-H5b-H5c, we used the frequency of social media use by employees as a moderator. Additionally, the analysis controlled for the effect of some control variables, such as age, gender, firm industry, and firm size (for details see Appendix 1).
Four regression models were estimated. Model 1 examines the direct effect of the four explanatory variables, of the moderator, and control variables on the employees' propensity to endorse the firm. In Model 2, Model 3, and Model 4, the interaction terms are included to test each of the three hypotheses regarding the moderating effects of the frequency of social media use by employees (H5a, H5b, H5c); the interaction terms are entered separately, in three different models, in order to avoid collinearity issues.
To uncover whether multicollinearity issues exist, we computed the variance inflation factor (VIF) for variables in Model 1. Data suggest that multicollinearity is not a concern because the values are lower than the threshold value of 3, ranging from 1.062 to 2.756.

Results
The results of the four regression models are presented in Table 3.
Model 1 reports the results from the base model without the interaction terms. The results show the positive association between employees' evaluation of their firms' social media strategy and employees' propensity to endorse the firm, supporting H1. Additionally, Model 1 suggests the existence of a positive association between encouragement to join social media conversations regarding the firm and employees' propensity to endorse the firm, supporting H4. However, the coefficients regarding both communication of policies and training programs on the use of social media are not significant, which leads to rejection of H2 and H3. The model also shows that the moderator (frequency of social media use by employees) is significantly and positively associated with employees' propensity to endorse the firm.
The results of Model 2 support the moderating effect of the frequency of employees' social media use on the relationship between communication of policies regarding social media use and employees' propensity to endorse the firm, thus confirming H5a. The interaction term turned out to be negative and significant, highlighting that the effect of the communication of policies on the employees' propensity to endorse weakens when the frequency of social media use by employees increases.
Model 3 finds support for hypothesis H5b, showing that the effect of training programs on the use of social media on employees' propensity to endorse is moderated by the frequency of social media use by employees. Specifically, the interaction term is negative and significant, suggesting that the effect of training programs on the propensity to endorse decreases when considering employees who use their social media profiles more frequently.
Finally, Model 4 shows that the moderating effect of the frequency of social media use by employees on the relationship between encouragement to join social media conversations regarding the firm and employees' propensity to endorse the firm is not significant. This evidence does not support H5c.
The moderating effects for which we found evidence are presented in Figs. 1 and 2. These figures show the relationship between the dependent and independent variable across two different levels of the moderator: low frequency of social media  Table 3 Regression analysis (Y = employees' propensity to endorse the firm) N = 224; *p < 0.10 **p < 0.05 ***p < 0.01. This table presents unstandardized beta coefficients use (calculated as one standard deviation below mean) and high frequency of social media use (calculated as one standard deviation above mean).

Discussion
This study is based on a questionnaire survey of employees, which allowed us to collect the voice of those who declared that they use their personal accounts on social media to talk about their firms. The aim of the study is to contribute to the under- standing of how firms may affect the propensity of such employees to endorse the firm. By directly asking individuals whether they are involved in online conversations about their firms, we had the opportunity to select a sample of employees that decided to talk about their firms on social media and we could thus deepen the analysis investigating which factors influence the way they talk about the firm. Indeed, the literature has highlighted that employees may talk in a positive way of their firm and recommend it and its products, contributing to improving brand reputation and even to co-creating the brand; at the same time, they may also damage their firms through their online communication (Cervellon & Lirio, 2017;Dreher, 2014;Parker et al., 2019;Rokka et al., 2014;Saleem & Hawkins, 2021). Consequently, firms are increasingly trying to manage the behavior of employees on social media in order to avoid risks and/or exploit potentialities associated with their participation in online conversations on the firm. We investigated the relationship between firm policies concerning social media and employees' propensity to endorse their firms. In particular, we hypothesized a potential role for both the firm social media strategy (and how it is perceived and evaluated by the firm employees) and policies aimed at influencing the use of social media by employees and favouring their endorsement (communication of social media policy, training, and encouragement to contribute to the online dialogue on the firm).
In regard to evaluation of the firms' social media strategy, the results support our first hypothesis according to which a positive evaluation by employees is associated with higher propensity to endorse the firm on social media. Appreciation for the communication strategy on social media contributes positively to the employees' overall evaluation of the firm and of its communication policy, and may thus enhance the employee-organization relationship and favour brand citizenship behaviours such as endorsing the firm through personal social media accounts. Moreover, this result suggests that employees prefer to explicitly support the firm on social media when this corresponds to associating their own image to an organization that-in that context, i.e., social media-adopts a strategy that they value. From the perspective of firms, it is thus important not only to adequately present their social media strategy to employees, but also to collect their feedback and monitor their perceptions and evaluations.
In regard to firms' policies regarding the use of social media by their employees, we tested the impact of three kind of initiatives -communication of social media policy, training, and encouragement to contribute to the online dialogue on the firm -in order to understand if they affect how employees talk about their firms. Model 1 shows that the encouragement is the only tested initiative that is positively associated to the employees' propensity to endorse their firm on social media. This result is in line with previous studies that highlight the importance of employees' perceiving that their commitment and engagement are relevant and appreciated (Cervellon & Lirio, 2017;Piehler, 2018). It also provides some evidence of the potential higher efficacy of an approach oriented at favoring and encouraging employees' active role on social media, compared to an approach mainly oriented at reducing risks by restricting employees' online participation (Mazzei & Butera, 2016). Extant literature has argued that encouraging employees to join the online conversation about the firm may enhance perceived authenticity and credibility thanks to the multiplicity of voices (Rokka et al., 2014). We add to this literature by showing that, among employees who use their personal social media accounts to talk about their firms, those who receive explicit encouragement to join the online conversation on their firms have a higher propensity to present their firms in a positive way and endorse them.
On the contrary, communication of policies concerning the use of social media and training, per se, do not turn out to be significantly relevant in explaining how employees talk about their firms.
However, because we expected that employees with different habits in terms of their social media use may react differently to the various initiatives that their firms adopt to manage their online behavior, we also tested the moderating effect of the frequency of employees' use of social media. Results of Model 2 show that the frequency of social media use negatively moderates the relationship between the communication of social media policies to employees and their propensity to endorse the firm. As shown in Fig. 1, firms' internal activities aimed at communicating social media policy are substantially irrelevant for heavy social media users, while they are positively associated with the propensity to endorse the firm in the case of employees whose frequency of social media use is low. This suggests that the communication of social media policy may contribute to favoring online endorsement of the firm by employees who are less accustomed to using social media. Given that these individuals tend to have lower knowledge regarding social media and how they can use them (Archer-Brown et al., 2018), a clear communication of the policies of the firm in this respect may help them understand their potential role as brand ambassadors and be more confident about their ability to act in a way that is in line with their firms' rules and expectations.
Similarly, results of Model 3 show that the frequency of social media use moderates the relationship between training and the propensity of employees to endorse their firm. More precisely, the negative moderation observed suggests that the effect of training programs on the propensity to endorse is beneficial only for employees who use their social media profiles less frequently (as shown also in Fig. 2). A possible explanation of this result is related to the fact that employees who are nonfrequent users probably benefit more from training concerning social media, given their relatively limited experience and competencies in regard to this tool. This, in turn, may lead them to increase their propensity to endorse for two possible reasons: on the one hand, it might have a positive impact on the overall evaluation of the firm; on the other hand, training may allow them to be more confident using social media and thus more open to accept to playing an active role in endorsing the firm on these media. This result confirms the importance of providing training on social media in accordance with the specific needs and competence gaps of employees (Walsh et al., 2020).
Overall, results of this study provide evidence that, in addition to encouragement, the communication of social media policies and training programs can enhance employees' propensity to endorse their employer. However, they highlight that the effectiveness of internal communication of policies and training initiatives differ in accordance with the intensity of the use of social media by employees, suggesting the need to focus these initiatives on non-frequent users.
The paper contributes to the literature investigating the role played on social media by employees and the policies that firms adopt to manage this (e.g., Cervellon & Lirio 2017;Dreher, 2014;Rokka et al., 2014). It answers the call for studies that collect the voice of employees (Mazzei & Butera, 2016), which are already relatively limited, and add to those based on the perspective of managers (e.g., Rokka et al., 2014).
By selecting a sample of employees that use their social media profiles to talk about their firms, we could focus the analysis on factors that may influence how these individuals talk about their employers. Given that employees may provide positive, neutral, or negative contributions to the conversation about their firms, it is particularly important to understand what influences the tendency to endorse of those who have chosen to be part of the conversation. From this perspective, our study adds to the literature contributing to a deeper understanding of the role played by firms' policies concerning social media in influencing employees' use of their personal accounts to endorse their employers. The study investigated the relevance of some policies that have already been suggested by the literature in order to test the actual presence of a positive relationship between these policies and the employees' propensity to endorse the firm. Results show that not all the identified tools have the same efficacy. Indeed, the communication of policies on social media use and training turned out not to have the expected generalized positive effect. Moreover, by revealing the moderating effect of the frequency of social media use, our results highlight how this characteristic of employees influences the effect of these policies and thus represent an important contingency to be taken into account by firms.
The paper has also managerial implications, given it suggests that the propensity to endorse the firm is favored by social media policies based on encouragement of employees (which overcome an approach based simply on managing risks through prescriptions and prohibitions). Results also highlight the importance of monitoring employees' perception of social media strategy, because a positive evaluation appears to be associated with a higher propensity to endorse the firm on social media. Moreover, the moderating effects observed suggest the opportunity to collect information on habits and competencies of employees in order to design more effective and focused initiatives. In particular, this study identifies the frequency of social media use as a first proxy that can be used to select target employees when allocating training resources and organizing internal communication initiatives.

Conclusions
Findings of this study suggest that firms can enhance their employees' propensity to endorse them online through policies concerning social media use (in particular, the explicit encouragement to talk about the firm through personal accounts) and their social media strategy (whose positive evaluation by employees affects their propensity to endorse the firm). However, results also suggest that some firms' initiatives (such as communication of social media policies and dedicated training) differ in efficacy in accordance with the frequency of social media use by employees. This highlights the importance of a dialogue with employees aimed at acquiring information on their habits in regard to the use of social media, as well as their evaluation of the firm's social media strategy. An implication of the findings is the need for marketing and human resource functions to coordinate to better design actions to promote employees' endorsement of the firm and focus them on adequate targets.
These results, as well as the limitations of the study, offer opportunities for future research in the field of both marketing and human resource management. In regard to human resource management research, future work might expand the study of characteristics of employees that affect the efficacy of firm policies aimed at promoting employees' endorsement. For instance, it would be interesting to investigate whether the effect of various policies differs between new hires and employees with more seniority within the firm. Another possible line of research concerns the implications of employees' endorsement on the capability of the firm to attract talent, comparing the effect of employees' joining conversations regarding the firm as their employer or conversations more focused on the commercial dimension, such as those regarding the brand and the products of the firm. Similarly, from the perspective of marketing research, a further step might involve investigating how employees' propensity to endorse and their online behaviors are related to brand reputation. Even in this case, it would be of interest to investigate whether there are different effects when employees are involved in conversations with different content, and to understand whether their influence on brand reputation is enhanced when employees explicitly communicate to be users of firm products.
A limitation of this study is its focus on the role played by initiatives specifically aimed at managing employees' behavior on social media and on employees' evaluation of the firms' social media strategies. Future research could expand on the analysis investigating the effect of other firm policies aimed at employees, including communication and training initiatives focused on the products, the brand, and the marketing strategies of the firm, as well as human resource policies such as welfare programs or work-life balance measures.
Moreover, the study focuses on employees that declared that they use their personal accounts on social media to join the conversation about their firms. In future studies, it would be of interest to collect the voice of employees who are exposed to firm initiatives regarding their use of social media but decide not to use their profiles to talk about their employers. In this regard, an aspect that deserves attention concerns the way employees perceive requests regarding the use of their personal social media profiles, given that some of them might not recognize the legitimacy of these requests or perceive them as an undesirable pressure.
Finally, we conducted regression analysis of data collected through a questionnaire addressed to employees, which allowed the voice of employees to be collected. Future studies, as those previously suggested, may require different approaches and methodologies, including qualitative studies.

Variables Description Dependent variable
The evaluation of the dependent variable was expressed on a 5-point Likert scale (from 1 "totally disagree" to 5 "totally agree") Employees' propensity to endorse the firm Item scale adapted from Morokane et al., 2015 Through social media, I talk up my firm to my friends as a great place to work Through social media, I bring up my firm in a positive way in conversations I have with friends and acquaintances Through social media, I often speak favorably about my firm Through social media, I encourage friends and acquaintances to buy the products and services of my firm Cronbach's Alpha: 0.917 Independent variables The evaluation of the independent variables was expressed on a 5-point Likert scale (from 1 "totally disagree" to 5 "totally agree") Employees' evaluation of their firms' social media strategy The level of agreement with the statement: "Your firm has an excellent social media strategy"

Communication of policies
The level of agreement with the statement: "Your firm has communicated to you a policy on the use of social media" Training The level of agreement with the statement: "You have received sufficient training on the use of social media from your firm" Encouragement The level of agreement with the statement: "Your firm encourages you to use your personal social media profiles to talk about the firm" Frequency of social media use by employees Measured through the level of usage of social media expressed by employees (more precisely, the variable was expressed on a 7-point scale, from 1 corresponding to "a few times a month" to 7 being "always connected")

Control variables Age
Continuous variable Respondents' age Gender Dummy variable for gender Industry Dummy variables for industries (more precisely, firms were classified into three industries: manufacturing and construction, wholesale and retail trade, and services) Size of the firm Measured through the number of employees (more precisely, firms were grouped into four classes on the bases of the number of employees)