Public service labor unions serve many functions, but their primary function is to maintain and improve working conditions. Effective public sector unions exist to enhance the satisfaction of public servants by improving their benefits and welfare. The constructive activities of public service labor unions improve administrative fairness and transparency by combatting authoritarian management styles and eliminating bureaucracy associated with human resources management issues. Since the activities of public service labor unions improve the welfare of public servants and administrative functioning, union effectiveness is crucial for achieving the ultimate goal of union stability over the long term.
The effectiveness of a public service labor union is closely related to the commitment of its members. Union commitment is very important to enhance the effectiveness of a public service labor union; likewise, a high level of union commitment can be achieved when union effectiveness is high. Therefore, it is important to identify the factors that influence the effectiveness of public service labor unions and union commitment in order to improve union effectiveness. Once identified, these factors can be adjusted in order to improve labor union operations. It is also important to examine the relationship between public service labor union effectiveness and union commitment.
Building on these ideas, I performed a study aimed at identifying factors affecting public labor union commitment and tested their significance. Additionally, I examined whether the perceived effectiveness of a union (based on perceived union utility and perceived public benefit) has mediating effects when these factors affect union commitment. The findings of this study may have implications for policymakers responsible for creating public service labor union policies and administrators responsible for ensuring effective union operations.
To fulfill the research purpose, I created 21 hypotheses based on a systematic review of the literature related to public service labor union commitment and effectiveness. To test the hypotheses, I collected survey data from 680 union members who belonged to one of 16 local governments. I used SPSS 21 for data analysis. I generated descriptive statistics for demographic variables, and performed t-tests and F-tests to determine differential effects. I used factor analysis and Cronbach’s alpha tests to assess factors of union commitment, and a bootstrapped PROCESS macro to analyze the mediating effects.
The results of the empirical analysis are summarized as follows with the main seven factors expected to affect union commitment (i.e., suitability of the union system, perception and attitude of the chief of the institution, perception and attitudes of colleagues, union leadership, individualism, collectivism, and the atmosphere of union relations). First, based on our analysis of factors affecting union commitment, I found that three of the seven tested factors (union leadership, collectivism and the atmosphere of union relations, in that order) have a significant effect on union commitment. Suitability of the union system had a negative effect on union commitment. Perception and attitude of the chief of the institution, perception and attitudes of colleagues, and individualism are not significant variables. Only the internal rank of union members turned out to be significant among the demographic variables. Moreover, union leaders were found to have higher union commitment compared to regular members.
Second, both perceived utility and perceived public benefit of the union significantly influence union commitment, albeit the influence of perceived public benefit is stronger. This result implies that union members consider the public benefit functions of the union and the utility of the union to be very important.
Perception and attitude among colleagues had complete mediation effect, and leadership of union executives had partial mediation effect on the perception of utility of union and the perception of public benefit of union. And individualism had complete mediation effect on the perception of utility of union.
Third, I found that perception and attitudes among colleagues, leadership of union executives, and individualism have mediating effects on the perceived utility of the union. And union leadership has a partial mediating effect on the perceived utility of the union. Perception and attitude among colleagues and union leadership have mediating effects on the perceived public benefit of the union. Moreover, I found that perception and attitudes among colleagues has a complete mediating effect, and union leadership has a partial mediating effect on the perceived public utility and the perceived public benefit of the union. And individualism had complete mediation effect on the perceived utility of union.
Given the current lack of research on union commitment in the public service sector, the results of this study have various important implications for union commitment and effectiveness that could prove useful for both policymakers and administrators of public service labor unions. Specifically: (a) the current public service labor union system must be improved in a flexible way; (b) it must be noted that perception and attitudes of union executives do not significantly affect union commitment and effectiveness; (c) union members should be provided with socialization opportunities; (d) it is important to expand investment in leadership training for union executives; (e) union leadership must embrace both individualistic and collectivistic union members; (f) the government should provide support such as developing programs to improve and establish sound labor relationships; (g) the perceived effectiveness of unions should be improved; and (h) strategies for union operations must be created with support from the government to harmonize the utility and public benefit of unions.

Key words: public service labor union, union commitment, union effectiveness, union utility, public benefit of unions, mediating effect