An Empirical Study of Affective Commitment: the Case of Machinery Enterprises in Hochiminh City

The study aims to investigate the impact of participation in decision-making (PDM) and perceived organizational support (POS) on affective commitment in machinery enterprises. The study applies structural equation modeling (SEM) to test the research hypotheses. The authors surveyed 220 employees who work in machinery enterprises to collect data for the research. The study results indicate that both PDM and POS positively impact affective commitment. The findings provide empirical evidence to support the theoretical models that PDM and POS have a positive effect on affective commitment. The findings have implications for management theory: PDM and POS are the key antecedents of affective commitment. The findings also have implications for practical management in the machinery enterprises that managers should practice both PDM and POS to increase affective commitment.


Introduction
Human resource management is playing a more important role in enterprise achievement. The enterprises should manage employees to promote affective commitment. Affective commitment is the employees' emotional commitment to the organization, thus affective commitment is the most important concept of organizational commitment (Mercurio, 2015). Affective commitment has been found as the key factor that has a positive relationship to employees' loyalty (Meyer & Maltin, 2010). The scope of research on affective commitment has increased and is related to factors impacting affective commitment. Knowing how to make employees have affective commitment is important to an organization because affective commitment helps enterprises grow and increases profitability. Employees always expect to participate in decision-making and receive organizational support in their tasks. If employees do not have the opportunity to present their thoughts and aspirations, they no longer feel excitement at work, and labor productivity decreases.
According to Northouse (2004), employees pay attention to their job performance and will commit to their organization if the managers recognize their contribution in decision making to improve the work process. When employees are involved in decisions to set goals and solve problems, satisfaction and performance are enhanced (Scott-Ladd et al., 2006). Therefore, employees should be motivated to participate in the PDM of the enterprise. This is the key to motivating employees to work hard and building a dynamic and self-reliant corporate culture where employees have the right to make decisions about their assigned work. Participating in decision-making increases job satisfaction and organizational commitment (Witt et al., 2000). In addition, the managers should improve the POS by recognizing the employees' effort toward the target, maintaining justice and ensuring employees' psychological well-being (Eisenberger & Stinglhamber, 2011). If the managers practice these behaviors, the employee will have positive attitudes such as affective commitment (Meyer et al., 2002). Due to the fact that affective commitment is a key determinant of organizational commitment, researchers and practitioners should pay attention to effectiveness in research and practical management (Mercurio, 2015).
The machinery industry in Hochiminh city includes more than 500 enterprises that produce machines and equipment. Most machinery enterprises do not have competitive advantages in comparison to the machinery enterprises in other Asian countries. Therefore, the machinery enterprises should change the technology as well as the management to enhance competitive advantages. In response to the growth trend, the managers of machinery enterprises need to increase employees' affective commitment to retain competent employees and facilitate high job performance. However, the authors' observations of machinery enterprises show that managers do not pay attention to affective commitment. There is an increase in conflict between employees and management, and employees take less responsibility for their work.
Through a pilot study of employees about the above problems, the authors find that the key factors causing conflict are failure on the part of management to comprehend the thoughts and difficulties of employees, which leads to their working inefficiently. Employees report that they feel that managers do not listen to their suggestions and complaints. Management principles, policies and regulations are issued without the agreement of employees. The enterprises are not concerned with employees' well-being and do not recognize employees' achievements. These problems show evidence that the machinery enterprises do not have good practice management related to PDM and POS.
Therefore, the first objective of this research proposes a model that shows the impact of PDM and POS on the affective commitment of employees. Secondly, this model would be applied to measure the impact level of PDM and POS on the affective commitment of employees at the machinery enterprises. Finally, the authors will offer suggestions about how to improve workers' PDM and perceptions of organizational support to increase the affective commitment of employees at businesses that produce machines in Hochiminh City.

Literature review
In the following paragraphs, the author will review the concept definition, develop the research hypotheses and propose the research model.

Concept definition
Affective commitment. Organizational commitment occurs when the employees are strongly involved in the organization (Meyer & Maltin, 2010), the employees accept the organization's goals and values (Carmeli, 2005), and the employees are emotionally attached to their organizations (Meyer et al., 2002). According to Allen et al. (1990), each component of the commitment is developed into a separate function and has different effects on the behavior of individuals at work. Meyer and Allen (1991) classified commitments into 3 forms, including affective commitment, continuance commitment and normative commitment. Meyer et al. (2002) proved that these types of commitment decreased turnover, and affective commitment had the strongest impact on expected employee behaviors such as attendance and performance. Meyer et al. (2002) also found that the three organizational commitments are different from each other as well as from job satisfaction. The definitions of the three organizational commitment concepts are as follows: Affective commitment: Affective commitment is defined as the emotional status when employees have a strong identification with and attachment to their organization's goals and values (Kim et al., 2016). The employees who have affective commitment want to devote their lives to the organization. With affective organizational commitment, employees want to be involved in the organization's values and goals ( Judge & Kammeyer-Mueller, 2012) and develop emotional attachment to their organization (Mercurio, 2015).
Continuance commitment: Continuance commitment is the psychological status when employees have commitment to their organization because they feel that they would lose benefits and pay a cost if they left their organization (Meyer & Allen, 1991). Continuance commitment helps employees have a close relationship with the organization and recognize that remaining as a member is a utilitarian necessity.
Normative commitment: Normative commitment is organizational commitment when the employees feel it is unethical behavior if they leave the organization (Meyer & Allen, 1991). Normative commitment is theoretical rather than experimental because this factor is less explicit than the two above-mentioned factors. Normative commitment represents the perception of employees that they are obliged to continue to work for the organization.
Affective commitment has the strongest impact on employees' behaviors such as attendance, performance, organizational citizenship behavior and employees' roles conflict (Meyer & Maltin, 2010). Affective commitment is related to other critical employees' behavior outcomes such as turnover, absenteeism, organizational citizenship behaviors and stress, so many researchers focus on exploring the factors impact on affective commitment (Meyer et al., 2002).. Affective commitment includes essential objectives that organizations should attain in management because it decreases the employees' negative behaviors and increases employees' positive behaviors, and affective commitment is also among the criteria to measure the organizational management effectiveness (Mercurio, 2015). In the next paragraph, the author will introduce the second concept in the research model: PDM.
Participation in decision-making (PDM). According to Kahnweiler and Thompson (2000), PDM is utilized when employees are involved in decisions about how the work is done, the way job performance is measured and what organizational objectives and policies are set. Similarly, according to Sharma and Kaur (2009), PDM is the scheme that the managers use to motivate the employees' participation in organizational decisions, but the employees do not have the authority to make these decisions. According to Elele and Fields (2010), PDM allows the employees to participate in an organization's decisions, but the control of the decisions belongs to the organization. PDM is different from empowerment in that empowerment is used to allow employees the rights to make decisions. PDM is one of the management methods to satisfy employees' needs and motivate employees at work. PDM empowers the employees to participate in decision-making to achieve organizational targets (Sagie & Aycan, 2003).
PDM is behaviors of the managers toward employees by encouraging them to be involved in decision-making processes (Beardwell & Claydon, 2007). It refers to employees directly involved in decision-making as well as being indirectly involved in decision-making through the labor union in the organization. PDM satisfies the employees' needs because employees have a need to have a voice and to be respected by the managers at work. Employees could participate in decision making for all stages of the work process, and a high level of PDM is correlated with higher organizational commitment, lower turnover and higher job performance (Scott-Ladd et al., 2006). Robinson et al. (2004) argued that if employees have the chance to participate in decision-making in the work process, they will have a good attitude toward the management, which will result in high job performance. Wood et al. (2012) indicated two categories that expand the employee's PDM: job design and teamwork. Employees could participate in decision-making by talking to the manager or labor union in the organizations. This participation in decision-making increases the perception that the managers respect them and their interests. In the next paragraph, the author will introduce the concept of POS in the study model.
Perceived organizational support (POS). Employees can evaluate organizational support and the effects it may have on organizational leaders' perceptions. When employees perceive that they are supported by managers, they will enjoy their work and have a positive perception of the organizational support. This concept is referred to as POS (Ahmed et al., 2011). POS is an increasingly important factor for management in the modern business world. According to Kim et al. (2016), POS is defined as the overall beliefs related to the organizations which greatly appreciate employees' work and want their employees to enjoy their jobs. Social exchange theory also shows that when an organization's rewards are given at the right time, and favorable working conditions are created for employees, they will feel more valuable and tend to contribute more to create additional POS.
POS is also understood as a guarantee that employees will always receive the support and assistance they need from the organization to effectively complete their work and to solve the problems in their work (Törner et al., 2017). POS also means that an organization's benefits compensate for the positive employee behaviors, as employees desire to work better to receive rewards and respect (Rhoades & Eisenberger, 2001). Krishnan and Mary (2012) defined POS as the employees' perception that the organization recognizes and appreciates their effort toward the organization's achievement. POS involves employees' perception that the organization appreciates their effort and pays attention to their needs (Kim et al., 2016). In return, POS reduces negative employee behaviors such as absenteeism, employee turnover and conflict and increases the positive employee behaviors such as job performance and citizenship behavior (Li & Tan, 2017). Many researchers have found that PDM and POS are the key factors that impact employees' commitment in different industries. The following paragraph will analyze prior research and form the hypotheses for this research.

PDM and affective commitment
Lok and Crawford (2001) found relationships between PDM and affective commitment. They proposed that affective commitment can be predicted by leadership that includes the participation and centralization in decision-making and awareness of employees about working conditions and also as beliefs about the supervision, participation in work and leadership style. PDM and the responsible expansion of the role of employees taking positive steps increase employee commitment to the organization. In addition, the previous studies also proved that PDM has positive impact on the affective commitment (Elele & Fields, 2010). These authors demonstrated that an awareness of work relates to affective commitment, and in order to increase that awareness, leaders should allow their employees to be involved more in decision-making.
PDM is the employees' demand, therefore they will value the organization if it satisfies their demand. In addition, PDM has a close relationship with job satisfaction and affective organizational commitment (Ladd & Marshall, 2004). PDM will satisfy the demand to respect employees. Employees feel the managers listen to their voices and value their opinions. That will motivate them and increase commitment to the organization. Therefore, PDM has become an essential management policy in organizational management and has the strongest impact on job satisfaction (Harmon et al., 2003;Zainnudin & Isa, 2011) as well as employees' organizational commitment and motivation (Batthi & Qureshi, 2007). When offered an opportunity to participate in decision-making, employees can change their perceptions, and a sense of fairness can be found among individuals in their relationships with their organizational leaders thereby leading to an increase in affective commitment and normative commitment of employees. Therefore, the satisfaction of employees on how organization leadership will meet with them, if necessary, will also strengthen affective commitment.
The survey of Dharmasri and Vathsala (2012) also showed that PDM has a positive impact on employees' affective commitment in the garment export businesses. This result makes sense: when an individual participates more in decision-making to fulfill his work responsibilities, this will lead to an increase in the integration of the individual within the organization, thereby strengthening the relationship between their PDM and affective commitment.
H1: PDM has a positive impact on affective commitment. Törner et al. (2017) stated that belief is a basis for affective commitment; the trust of the employees in the manager will be built on the foundation of the relationship between the employees' belief in organization and affective commitment; a high support level from the organization creates an obligation in the employee not only to commit to the organization, but is also expressed in behaviors that attempt to meet the goals of the organization. According to Aselage and Eisenberger (2003), the employee will feel obligated to help those who have supported him or her. Their perception of organizational support will create a desire in the employee to respond to the organization, which in turn can be seen as the employees invest their affection in the organization.

POS and affective commitment
In the study of Aube et al. (2007), comparing POS with other components of organizational commitment shows that POS takes on high significance in increasing affective commitment. Eisenberger and Stinglhamber (2011) confirmed that POS closely correlates with affective commitment. In cases where the individual feels valued and supported by the organization, the affective attachment to the organization will be higher. Meyer et al. (2002) commented that the more employees are aware that they are treated favorably by an organization, the more their affective commitment will be, and the expression of negative behaviors will decrease. Meyer et al. (2002) also found that a change in POS will lead to a change in affective commitment, therefore POS is a primary foundation which contributes to the creation of affective commitment. This relationship occurs through the mediation of social-affective needs implementation such as are found in the spiritual connections and support among individuals in the organization. Rhoades and Eisenberger (2002) stressed that POS, which can be attained by connecting members of the organization, promoting their roles, positions and social value, can also increase affective commitment. Due to the affective commitment generated on expected organizations and employees' outcomes, many studies focus on finding the antecedents of affective commitment. The previous studies showed that POS has the strongest impact on affective commitment (Kim et al., 2016). Employees with higher POS will place more thought on purpose and means through their affective commitment to the organization.

H2: POS has a positive impact on the affective commitment.
Through an overview of previous research and the above hypotheses about the relationship between PDM, POS and affective commitment, the author proposes the following conceptual research model:

Sample and data collection
The authors conducted the study in 500 enterprises that produce machines and tools in Hochiminh city. There are 135,566 employees working in this industry including indirect employees and workers. The population of the study includes 27,000 indirect employees who work in different departments such as sales, accounting, operating and purchasing. The authors applied the minimum sample size standard for a CFA and SEM analysis of 150 with a model of 7 or fewer concepts (Hair et al., 2014). The study has fewer than 7 concepts, and the sample size should include at least 150 respondents. The sample was selected for the study by a convenience method. The authors selected 23 machinery enterprises and distributed 10 questionnaires to employees in each machinery enterprise. A total of 230 questionnaires were distributed to the respondents. There were 227 respondents who returned the answered sheets; the response rate was 98.6 percent. However, only 220 completed answer sheets qualified for data analysis, therefore the sample includes 220 respondents who meet the sample size standard. Table 1 shows that respondents in the study sample were of different age, gender, experience, seniority, and education levels. Therefore, the respondent profile represents the population of employees in the machinery enterprises.

Scale measures
The first independent variable, employees' PDM, was measured by a 5-point Likert scale (White & Ruh, 1973). The second independent variable, POS, was measured by 17 scale items (Eisenberger et al., 1986). Dependent variables of affective commitment were measured by a 6-point scale (Meyer et al., 1993). The 5-point Likert scale corresponds to the following: 5 -Strongly agree, 4 -Agree, 3 -Neutral, 2 -Disagree, 1 -Strongly disagree. All the variable scales in the research model were implemented by a reliability test. The final results of the reliability test show that the values of Cronbach's alpha of all variable scales range between 0.810 and 0.927. These are higher than the criterion value of 0.6. All scale items have an Item-Total Correlation of over 0.3 (Hair et al., 2010). Therefore, all the scales are considered reliable to measure the variables in the model of the study.  Table 2 also shows the mean values and standard deviations for the independent variables and the dependent variables. The results of the descriptive statistics indicate that workers agreed on PDM (mean = 3.05, std. = 0.827), POS (mean = 3.14, std. deviation = 0.677) and affective commitment (mean = 3.38, std. deviation = 0.742). Descriptive statistics generally indicate that respondents agreed with statements related to affective commitment, perceived supervisor support and PDM at moderate levels. Affective commitment had mean values greater than those of perceived supervisor support and participation in decision-making.

Measurement model
The CFA analysis process requires the researcher to conduct the exploratory factor analysis (EFA) by principal axis factoring and promax rotation. The first time has KMO = 0.928 > 0.05, and the Bartlett's test has Sig. = 0.000, which shows that EFA is suitable. However, the POS1, POS2, POS7, POS10 and PDM5 have factor loading < 0.5 and were deleted to conduct the next EFA (Hair et al., 2009). The EFA in the second time has KMO = 0.926 and the Bartlett's test has Sig.= 0.000, which shows that EFA is suitable. The Eigenvalues = 1.676, and the data is extracted into the 3 factors in the research model. The variance cumulative percent = 53.03, which means that extracted factors explain nearly 53.03% of the variability in the original 3 variables in the research model (Hair et al., 2009). The results of EFA analysis indicate that POS remains in 13 items, PDM remains in 4 items and affective commitment remains in 6 items. The model fit is measured by confirmatory factor analysis (CFA). The results of the CFA show that all the indices exceed the cut-off level as follows: χ2 = 1.824 was lower than 3, CFI = 0.932 was greater than 0.9, GFI = 0.865 was greater than 0.8, TLI = 0.923 was greater than 0.9 and RMSEA = 0.061 less than 0.08 (Hair et al ., 2010). These results exhibited in Figure 2 indicate that the measurement model demonstrates a good level of model fit:  Table 5 shows that the composite reliability (CR) of all constructs was greater than 0.7, and the average variance extracted (AVE) of all constructors was greater than 0.5 (Hair et al., 2010). Furthermore, the AVE estimates of the constructs are greater than the squared correlations. These results show that the measurement model is valid and reliable.

Hypotheses test
The SEM analysis was conducted to test the research hypotheses. The results of the SEM analysis indicate the model fit to the data, and all the tests meet the suggested thresholds as follows: χ 2 = 1.964 was less than 3, CFI = 0.920 was greater than 0.9, GFI = 0.858 was greater than 0.8, TLI = 0.910 was greater than 0.9 and RMSEA = 0.066 was less than 0.08 (Hair et al., 2010). The results of the hypotheses test are shown as follows:  Table 5 indicates that hypotheses H1 and H2 are accepted. POS significantly impacts on affective commitment (β = 0.617, p < 0.01). PDM significantly impacts on affective commitment (β = 0.120, p < 0.06). The regression weights show that the perceived organizational support has the strongest impact on affective commitment.

Discussion
The SEM analysis results indicate that PDM and POS both have positive impact on affective commitment. In particular, POS has the stronger impact on affective commitment (β = 0.617, p < 0.01). This finding explains that employees expect the enterprises to support them in their work. This support includes proper working conditions, problem solving, performance appraisal and benefits. If they perceive proper organizational support, they will have affective commitment (Rhoades et al., 2001;Aube et al., 2007;Kim et al., 2016). The results also indicate that PDM has a significant but lower impact on affective commitment (β = 0.120, p < 0.05). This finding explains that the employees involved in decision-making will affectively commit to the organization. The research results contribute to both theoretical management and practical management (Angle et al., 1981;Decotiis et al., 1987;Lok et al., 2001).
In the theoretical contribution, the study results propose a study model of affective commitment that includes PDM and POS. There are some scholars who have combined PDM and POS to conduct studies on affective commitment. Other scholars often study affective commitment with familiar independent variables such as pay, promotion, manager's support, working conditions, training, and colleague relationships. Besides, some scholars have conducted research with similar study models in developing countries. This study is one of the first studies to test the impact of PDM and POS on affective commitment in the emerging markets. The study results show more evidence that PDM and POS have an impact on affective commitment in a different research context. The results of this study confirm that PDM and POS are the predictors of affective commitment. Especially, POS has a strong impact on affective commitment and should be considered as a key antecedent of affective commitment (Alnaimi & Rjoub, 2019). Therefore, scholars should pay more attention to PDM and POS in the study of affective commitment.
In terms of practical contributions, the study results show that both PDM and POS positively impact affective commitment. The study results provide a tested model for the managers to understand PDM and POS impact on affective commitment. The study results also provide variable scales for managers. The managers could take the study model and variable scales to apply in practical management to promote affective commitment. The findings also indicate that the managers should pay attention not only to pay, incentives, and working conditions, but also to POS and PDM to increase affective commitment. If the employees perceive that they participate in decision making in their working process, and the enterprise supports them in their job, the employees will have affective commitment. The managers should consider the practical implications of conducting POS and PDM mentioned in the following paragraph.

Practical implications
The implication for PDM is that the managers in the machinery enterprises should motivate the employees to participate in decision making in the work process. PDM is the basis for building an effective working environment, and employees who work in this type of environment have the opportunity to maximize their capability. The employees have a sense of responsibility for work, and the cooperation and mutual support among colleagues is also increased. As a result, the employees certainly perceive the machinery enterprises as the second family they attach their life to and devote their effort to achieve the enterprise's mission and goals.
The employees are ensured that they have a voice and influence on the work process in order to choose the best methods to complete their work. The employees can participate in decision making when the enterprises make plans, solve problems and revise policies and regulations. The managers should listen to and recognize the employees' opinions. In addition, managers should create a positive democratic climate, including teamwork culture and open communication. The managers should hold monthly meetings and other social dialogue in the enterprises so that the employees have more chances to voice their opinions because organizational climate, well-organized teamwork and good communication were found to have positive impact on PDM (Cadwallader et al., 2010).
The implication for POS is that the managers always show that they care for their employees. The managers should understand the employee's needs and values and satisfy the employee's needs and values to promote affective commitment. They should establish work conditions in clean, safe places with appropriate equipment for employees to perform their jobs. Favorable working conditions are an important factor affecting the level of affective commitment of employees. The managers should conduct a performance appraisal to measure job performance and recognize the employees' effort and performance to reach the targets.
The managers should design good benefit plans to motivate the employees. Good benefit plans such as social insurance, bonus, allowance, vacations, holiday, health care, and flexible working hours will increase the perception of organization support (Alhmoud & Rjoub, 2019). Especially, the managers' reward for innovations that improve technology, increase labor productivity and cut production costs is essential. The managers should support employees when they encounter problems in their work. Every time the employees ask for support, the managers should be willing to help them solve the problems in the job as well as in their life. The managers should show social responsibility and ethics to the employees. The managers should treat the employees with justice and encourage career development to promote affective commitment.

Limitations
The sample size of this research is large enough to meet the standards for data analysis. The author was able to select 220 employees in machinery enterprises by a convenience sampling method. The author could not select a sample by quota method to ensure the same percentage of employees in each enterprise. The author could not conduct an in-depth interview with employees to understand the practice of POS and PDM in enterprises in detail. The foreign direct investment enterprises in this industry were not included in the sample size to compare the difference between the practice of POS and PDM. Therefore, the generalizability of the results to this or other populations is not high. Therefore, to enhance the value of this research, better representative sampling methods such as probabilistic sampling should be used in future studies. Additionally, researchers should also increase the sample size for better factor analysis results. The research model includes only two independent variables impacting affective commitment to organizations. Therefore, many other factors have not been considered such as perceived job fit and intrinsic motivation. This research only considered one component of organizational commitment, which is affective commitment. The two remaining components, including continuance commitment and normative commitment, have not yet been considered. Therefore, in order to have a more complete body of research, these two components should be considered. The study does not bring anything new to the literature with the exception of showing that PDM and POS positively impact affective commitment in emerging economies such as Vietnam. Meyer et al. (2002) suggested that more research on organizational commitment among different cultures is necessary to make the comparison. In the future, the author also intends to do research on relations between commitment and organizational change in Vietnam. Meyer et al. (2002) and our work both found considerable support for the relationship between commitment and organizational change.