The Impact of High-Performance Work System on New Generation Employees’ Turnover Intention: Psychological Capital as Mediator and Perceived Organizational Support as Moderator

Based on the social exchange theory, this study uses questionnaires from 313 employees to discuss the impact mechanism of high-performance work system on new generation employees’ turnover intention, and introduces psychological capital and perceived organizational support. The study draws assertions from related concepts of psychological capital and perceived organizational support to determine relationships between high-performance work system and new generation employees’ turnover intention; psychological capital, perceived organizational support and turnover intention. Through empirical analysis, it is found that there is a significant negative correlation between high-performance work system and new generation employees’ turnover intention; psychological capital partially mediates the relationship between high performance work system and turnover intention of new generation employees; perceived organizational support plays a moderating role between psychological capital and new generation employees’ turnover intention. Through empirical analysis, we hope to provide some suggestions for enterprises to reduce the turnover rate of new generation employees.


Introduction
Excellent talents are the important capital for the prosperity of enterprises and country. In recent years, with new generation employees gradually entering the workplace and becoming an important pillar for the development of enterprises, the research on the management of new generation employees has been paid more and more attention. New generation employees have active thinking and strong acceptance ability, but they are also prone to turnover. According to the 2017 Turnover and Salary Adjustment Research Report released by 51 Job Survey, the turnover rate of new generation employees continued to increase from 2014 to 2016. In 2016, the proportion of new generation employees who quit voluntarily accounted for 26.5%, much higher than the average social voluntary turnover rate of 16.0%. For enterprises, appropriate staff turnover is beneficial to maintain the vitality and healthy development of enterprises, but new generation employees work is the foundation of the prosperity and development of modern enterprises, their frequent turnover behavior will have a negative effect on themselves and their organizations.
On the one hand, with the rapid development of Internet and the acceleration of economic globalization, the restriction between region and information sharing has been broken and the speed of staff turnover has increased; on the other hand, because the birth and living environment of new generation employees are different from that of the old generation, it also determines that the personality, lifestyle and habits of new generation employees will be very different from those of old generation. They do not like to be restrained; they are more eager to realize their own value and pursue themselves in an open and fair environment. They like to take risks, are unwilling to be mediocre, and have the courage to say go. The unique personality and thinking of new generation employees not only add vitality and new strength to enterprises, but also put forward new challenges to the traditional practice of human resource management in the process of employment. Unilateral human resource practice activities can't influence the attitude and behavior of new generation employees to achieve good results for the enterprise. The systematic combination of human resource practice-high performance work system plays a good role in improving the attitude and behavior of employees, improving organizational performance and reducing turnover rate (Wu & Chaturvedi, 2009;Zhang & Morris, 2014;Alfes, Shantz, Truss, & Soane, 2013).
Foreign scholars began to study the relationship between high performance work system and turnover rate since the 1990s. However, most of the domestic discussions on high performance work system focus on its impact on organizational or enterprise performance. Therefore, the study starts with high performance work system in Chinese context, discusses its influence and mechanism on the turnover intention of new generation employees based on the social exchange theory, and introduces psychological capital and organizational support as mediating variables and moderating variables respectively, hoping to provide some ideas for enterprises to retain new generation employees.

High-Performance Work System and Turnover Intention
In reality, a series of human resource management practice activities that employees come into contact with have an impact on employees' attitudes and behaviors as a whole; so human resource management system has gradually become a research hotspot. Traditional management methods, such as Taylor's scientific management theory, are not enough to deal with the open and changeable market environment and independent employees. Therefore, scholars put forward various human resource practices of "people-oriented", among which the most representative practice is high-performance work system (HPWS). High performance work system is regarded as a series of human resource practice activities to improve employees' skills, commitment and productivity, which makes employees become the source of sustainable competitive advantage. It is a series of human resource management practices implemented by organizations as a whole to analyze their impact on individuals or organizations (Huselid, 1995). At present, there is no uniform regulation for the content of complete high performance work system, but it usually includes recruitment and selection, incentive pay, performance appraisal, extensive employee participation and welfare, etc.
Turnover intention refers to the psychological state of employees who have worked in the organization for more than a certain period of time and decided to leave the existing organization after careful consideration (Mobley, 1977).
New generation employees pay more attention to the organizational atmosphere and are more suitable for flexible and people-oriented human resource practice activities. Standardized performance appraisal, reasonable on-the-job training system, strict recruitment process and good welfare policies ensure the working atmosphere of employees; encouraging communication between employees and their superiors and colleagues can ensure that employees get work-related information in a timely manner and improve their sense of security; rewarding and motivating outstanding employees in a timely manner can make them work harder and feel that their efforts can be rewarded accordingly. Therefore, according to the social exchange theory, employees will try their best to show a positive attitude and behavior in order to repay the organization after sensing the efforts of enterprise to implement a series of positive human resource practice measures, and tend to stay in the organization for a long time to create more wealth. Selden & Sowa (2015) explored the relationship between high-performance work practices and turnover intention based on the sample of voluntary turnover of non-profit organizations in eight states of the United States in 2015. The study found that some high-performance work practices such as induction training, leadership development, salary and employee relationship were negatively related to turnover intention. Therefore, the following assumption is proposed: H1: High performance work system is negatively correlated with turnover intention of new generation employees.

High-Performance Work System, Psychological Capital and Turnover Intention
Psychological capital refers to a kind of positive psychological state in the process of individual growth and development, which is embodied in four aspects in work: self-efficacy, optimism, hope and resilience (Luthans, Youssef, & Avolio, 2007). At the organizational level, psychological capital has the characteristics of competitiveness, value-added, relative independence and so on. It is one of the important driving forces to stimulate individual development potential and help enterprises succeed in the fierce competition. The organization that establishes high performance work system adopts the open and fair performance appraisal method and strict recruitment method to make employees feel the fairness in the organization, so that employees will have more trust in the organization and more confidence in completing work tasks; adopting the way of information sharing can enable employees to understand the enterprise objectives in time and communicate with the organization in time about the problems existing in the work, and reduce the work pressure caused by poor communication and information asymmetry; extensive training can make employees' working ability and working methods keep pace with the times, and reduce employees' frustration caused by not keeping up with the times or technological changes; welfare policy and employee motivation can make employees have a clear understanding of the future career path and full of hope for their own work prospects while getting care and encouragement. Through empirical research, Fei Zhou & Chuanqing Zhang (2012) found that high performance work system has a positive role in promoting employees' psychological capital. Therefore, the following assumption is proposed: H2: There is a significant positive correlation between high performance work system and psychological capital of new generation employees.
According to Hbofoll's resource conservation theory, the more resources an individual has, the less vulnerable he is to be harmed by the loss of resources. Individuals who lack resources are not only vulnerable to the negative impact of the loss of resources, but also may cause employees to invest more other resources in order to prevent the occurrence of greater losses, resulting in resources beyond their means (Hobfoll & Stevan, 1989). As a kind of positive psychological resources, psychological capital can encourage individuals to face the problems in work actively. When psychological resources are insufficient, individuals will seek new resources and need to give up existing resources. If the resources need to be given up are related to work, employees will easily have the intention to leave.
Avery and others think that employees with positive psychological state can actively complete tasks in the organization. Even if things do not happen as they expected, hope and optimism will also positively affect their loyalty to the organization. Since then, they have conducted empirical analysis on 416 employees in different industries, and the research shows that psychological capital has significant inhibition on turnover intention (Avey, Luthans, & Jensen, 2009). (2017) based on 217 samples of service industry, also found that psychological capital significantly negatively affected turnover intention.

Gupta & Shaheen
Therefore, we propose: H3: The psychological capital of new generation employees is negatively correlated with turnover intention.
The influence of human resource practice on employees' attitude and behavior needs to affect the perception of employees, and then affect employees' turnover intention and organizational performance (Yan, Zhao, & Yu, 2017). Luthans found that psychological capital can be greatly improved in a short period of time through network-based training, intervention and other measures (Luthans, Avey, & Patera, 2008). Through a series of human resource practice activities, the level of psychological capital of new generation employees will be affected to some extent. As a kind of positive resource owned by individuals, psychological capital can improve employees' psychological endurance, stimulate employees' potential, make employees full of motivation, and will not escape when they encounter difficulties in work. Therefore, we propose: H4: The psychological capital of new generation employees mediates the effects of high performance work system on turnover intention.

The Moderating Effect of Perceived Organzational Support
Eisenberger put forward the organizational support theory in the mid-1980s according to "mutual benefit norms" and "social exchange theory". The theory holds that when employees feel the support, concern and recognition of the organization, they will respond well in their work (Eisenberger, Huntington, Hutchison, & Sowa, 1986). Based on the social exchange theory and organizational support theory, Eisenberger points out that employees form an overall view of whether the organization values their contributions and gives them different treatment in different situations, that is, employees' perceived organizational support (POS). According to the theory of emotional events, employees' experience in the working environment can induce different emotional reactions, which will further affect individual attitudes and behaviors (Weiss & Cropanzano, 1996). As an employee's perception of external environment incentives, organizational support may have an effect on the influence of psychological resources on employees' attitudes and behaviors in the process of work. When perceived organizational support is low, the negative emotion accumulation of new generation employees will make employees have a pessimistic attitude. According to the theory of emotional events, under the double attack of the loss of positive psychological resources and organizational support, employees will be more inclined to leave the current organization and look for other better organizations. According to Maslow's "hierarchy of needs theory", new generation employees meet the needs of the lower level in the early stage because of their good birth environment and economic conditions, so they will be more inclined to pursue higher needs. Perceived organizational support can make employees feel the care, respect and recognition of the organization, and the high-level needs of new generation employees will be met to a certain extent, which will generate positive emotions. Good emotions are conducive to the psychological development of employees, the physical and mental happiness of employees will be more inclined to meet the current state and reduce new generation employees' turnover thoughts. Wang Yanfei et al. (2017) used perceived organizational support as a moderating variable for empirical analysis, and found that it played a moderating role in the influence of psychological capital on employees' attitudes and behaviors. Therefore, we propose the hypothesis: H5: New generation employees' perceived organizational support plays a moderating role in the relationship between psychological capital and turnover intention.
The theoretical framework of the study is shown in Figure 1.

Research Sample
In this study, the platform for collecting questionnaires is wenjuanxing, which is widely used in china. Respondents are new generation employees. The collected questionnaires were screened according to the relevant requirements to find out the age discrepancy and invalid questionnaires (for example, half of the questions in a row chose the same option or obvious regular answers). A total of 475 questionnaires were collected. After screening out unqualified questionnaires, 313 were valid, and the effective recovery rate was 65.89%. According to the sample size statistical formula: , when the confidence interval is 90%, σ is 0.5 and d is 5%, N is 271. We have collected 313 valid questionnaires, which meet the requirements. As shown in Table 1, in terms of gender, male accounted for 45.05%, female 54.95%; in terms of age, 18 -22 years accounted for 20.13%, 23 -27 years accounted for 61.34%, 28 -33 years accounted for 18.53%; in terms of the highest education, junior college and below accounted for 17.89%, undergraduate accounted for 75.4%, master's degree and above accounted for 6.71%; in terms of working years, less than one year accounted for 23%, 1 -3 years accounted for 53.99%, 4 -6 years accounted for 18.53%, 7 -10 years for 4.15%, More than 10 years accounted for 0.32%.

Measures
The variables involved in the study are all measured by Likert 5-point measurement method, with 1 -5 indicating "very consistent" to "very inconsistent".   et al. (1979). And there are four questions in total.
Control variables: in order to control the influence of individual characteristics of new generation employees on high performance work system and turnover intention, the following variables were selected as control variables: 1) gender: set as male and female; 2) age: set as 18 -22 years old, 23 -27 years old, 28 -33 years old and others, so as to facilitate the selection of employees born after 1985; 3) the highest education level: Set as junior college or below, undergraduate and master degree or above; 4) working years in the current enterprise: set as less than 1 year, 1 -3 years, 4 -6 years, 7 -10 years and more than 10 years.

Descriptive Statistics
In this study, SPSS 23.0 was used to calculate mean value and standard deviation of each variable, and the correlation between variables was analyzed. It can be seen from Table 2 that high performance work system has a significant positive impact on psychological capital (r = 0.559, p < 0.01), perceived organizational support (r = 0.549, p < 0.01), and a significant negative impact on the turnover intention of new generation employees (r = −0.347, p < 0.01); psychological capital of new generation employees has a significant positive correlation with perceived organizational support (r = 0.415, p < 0.01), and a significant negative correlation between psychological capital and turnover intention (r = −0.294, p < 0.0 1). There was a significant negative correlation between perceived organizational support and turnover intention (r = −0.185, p < 0.01). This shows that the correlation between the variables in this study is good, which lays a certain foundation for the follow-up statistical analysis.

Results
In this study, SPSS23.0 software was used to test the hypothesis through hierarchical linear regression analysis according to the intermediary effect test program proposed by Baron & Kenny (1986). As shown in Table 3, the age, gender, highest education background and working years of employees are the control variables of the study. Model 2 tests the relationship between high performance work system and turnover intention of new generation employees. According to the regression results, high performance work system and turnover intention of new generation employees (β = −0.574, p < 0.001) are significantly negatively correlated, so H1 is supported. Psychological capital was included in model 5 as a dependent variable for regression analysis. It was found that there was a significant positive correlation between high performance work system and psychological capital of new generation employees (β = 0.562, p < 0.001), so H2 was supported. When high performance work system and psychological capital are   ployees has a partial intermediary role between HPWS and turnover intention, and H4 is supported.
In order to avoid multicollinearity, we should first follow the general paradigm of regulatory effect and standardize psychological capital and perceived organizational support. As shown in Table 4, demographic variables are taken as control variables first, and then psychological capital is included in model 2.
Psychological capital of new generation employees is negatively correlated with turnover intention (β = −0.491, p < 0.001), so H3 is supported. In model 4, the interaction between psychological capital and perceived organizational support had a significant impact on turnover intention (β = −0.124, p < 0.05), so H5 was supported. In other words, new generation employees' perceived organizational support will enhance the negative effect of psychological capital on turnover intention.
In order to further verify whether the mode of action of moderating effect is consistent with the hypothesis, we draw a schematic diagram of regulatory effect trend. As shown in Figure 2, dotted line represents high pos, solid line represents low pos, and the slope of dotted line is larger than that of solid line. This shows that the lower perceived organizational support, the weaker the relationship between psychological capital and turnover intention, the higher perceived organizational support, the stronger the relationship between psychological capital and turnover intention. That is to say, perceived organizational support enhances the relationship between psychological capital and turnover intention.  It can be concluded that new generation employees' perceived organizational support regulates the relationship between psychological capital and turnover intention.

Research Conclusion
Through empirical research, we find that the influence mechanism of high performance work system on turnover intention of new generation employees, as well as the mediating role of psychological capital and the regulating role of per- 1) high performance work system has a significant negative impact on the turnover intention of new generation employees. The perfect human resource practice can help employees better plan their own career path, promote the communication between the upper and lower levels and departments, enhance the sense of belonging of employees, so that the labor union is more inclined to stay in the organization; 2) psychological capital partially mediates the relationship between high performance work system and turnover intention of new generation employees. The more perfect the high performance work system in the organization, the more positive psychological resources employees have and the higher their psychological capital level. They will first have a positive attitude and view towards things, will actively integrate into the organization, and will actively solve problems and difficulties, rather than choose to escape, which will reduce the turnover intention of employees to a certain extent; 3) perceived organizational support plays a moderating role between psychological capital and turnover intention of new generation employees. Perceived organizational support will enhance the weakening effect of psychological capital on turnover intention.

Managerial Implications
First of all, we should improve high performance work system. The enterprise shall devote certain energy to develop a management activity plan that is more So organization should combine the characteristics of new generation employees to approach employees, for example, through the establishment of we chat group to further communicate with employees, properly understand the difficulties encountered in their lives and work and help them, so that employees have no worries.

Limitations and Directions for Further Results
The variables selected in this study are analyzed as a whole, and there is no specific analysis of the impact of a series of human resource practices in the high performance work system, such as training, employee participation, welfare care and so on. In the future research, we should consider from the specific human resource practice to explore their impact on the turnover intention of new generation employees. In addition, this study theoretically explains the relationship between the variables, but the cross-section design is adopted, so the longitudinal data of a larger time span can be used to better verify the causal relationship between variables in future research.