1. Introduction
United Nations has encouraged organisations to voluntarily adopt sustainable development goals (SDGs) in business strategies to promote human sustainability, which many global companies have embraced. In this context, the perspective of interactions of SDGs for human sustainability at work [
1] emphasises that decent (adverse) working conditions (SDG-8) are essential aspects of the health and well-being of the working population (SDG-3). Many definitions exist in the literature for employee well-being [
2,
3]. However, we chose to use Van Laar, Edwards, and Easton’s [
4] definition of employee well-being in this study which relates to the quality of work life or work-related quality of life, to examine the human dimension of sustainability.
The human dimension of sustainability [
5,
6] uses health harm of work (HHW) as a leading indicator to develop responsible/decent human resource management (HRM) practices (SDG-8) that enhance employee well-being (SDG-3). In particular, the HHW approach examines restrictions imposed by work on employees’ human energy as a resource to achieve positive health and well-being outcomes [
7,
8]. This view differs from the work recovery experience, which typically emphasises mood regulation and job-stress coping [
9].
The human energy discussed in the definition of HHW represents a source of “fuel” necessary for an employee’s work performance and to involve in non-work activities to enhance well-being [
10]. When this finite form of human energy lessens due to the cumulative negative effect of working conditions (SDG-8), it is questionable whether organisational support will facilitate subordinates coping strategies to buffer employee well-being (SDG-3). The ceiling effects of human energy help explain this phenomenon. The ceiling effect argues that the human energy trough or limit reached by high levels of human energy depletion resulting from cumulative adverse work experiences inhibits employee well-being [
11]. The theory further argues that the employees’ additional organisational resources, such as supervisor support [
12] and supervisory political support [
13], which facilitates employees’ resource gain cycle, have only a modest effect on employee well-being, if any, beyond the human energy trough.
The ceiling effect of human energy theory extends the Conservation of Resources (COR) theory [
14]. The COR principles explain the critical motivation for employee decisions to maintain and foster resources to manage the resource loss cycle during the current work demands. Subsequently, to acquire resources in the resource gain cycle to guard against further depletion in adverse work contexts. According to COR principles, resource loss and gain are independent cycles. However, in extending the COR principles, the ceiling effect highlights the human energy limit or trough between resource loss and gain cycles which explains the variability in employees thriving for work performance and well-being outcomes. That is, the human energy trough between resource depletion and gain cycles must be short to improve the well-being dimension of human sustainability (SDG-3). However, even with personal and organisational motivational sources for resource gain, it is less likely to guard against resource depletion due to cumulative adverse working conditions (SDG-8) to shorten the human energy trough. Shortening the human energy trough between the resource depletion and gain cycles is essential to plan and develop socially responsible HR practices from the sustainable HRM perspective to help employees allow their biological system to naturally reverse itself to gain human energy for future work performance and well-being.
In the health literature, well-being includes health and constitutes a unifying concept (including medical and non-medical priorities) valuable for health improvement [
15]. In the management literature, subjective well-being is a broad construct that includes life satisfaction and job satisfaction which reflects positive and negative affectivity or feelings/emotions toward working conditions of jobs [
3]. The job quality perspective of well-being is about the extent to which a job has work characteristics and employment-related factors that facilitate favourable or unfavourable feelings for the employee [
16]. Following this tradition, we explored the employee well-being dimension of human sustainability from the sustainable HRM perspective using positive and negative affectivity towards working conditions of jobs.
Previous studies in the occupational health and management literature explored using COR theory the buffering role of organisational resources (e.g., supervisor support and supervisor political support) on the relationship between job stress and employee well-being [
17]. Evidence-based on COR theory suggests that supervisor support [
12] and supervisory political support [
13] tend to positively buffer the ‘silo’ or isolated adverse effect of work (e.g., job tension, work stress) and well-being. However, in this study, we use the ceiling effect of the human energy perspective [
11] from sustainable HRM to understand the buffering role of organisational support, such as supervisor political support, on the relationship between chronic or ‘cumulative’ harmful working conditions (adverse SDG-8) experienced by employees and employee well-being as a dimension of human sustainability (SDG-3). Supervisor political support (SPS), which is different from supervisory support, focuses on supervisors’ non-sanctioned (political) actions taken to enhance the well-being of one’s subordinates [
13]. However, perceived supervisory support [
12] explains the support supervisors provide to their subordinates within the scope of a formal supervisory role.
Understanding the synergistic, adverse effects of work characteristics and SPS on organisation and stakeholder (i.e., employees) outcomes from the ceiling effect of human energy viewpoint is essential for the emerging field of sustainable HRM to gain insights into the temporal perspective [
18] on the ongoing adverse effects of work on stakeholders. This empirical evidence will help organisations develop strategic corporate social responsibility initiatives to minimise cumulative adverse working conditions imposed on stakeholders (i.e., employees, families, and society) to facilitate SDG-3. Hence, we explore the three-way interactional or synergistic effect of SPS in facilitating HHW—job tension negative complementarity on well-being based on the ceiling effect of the human energy perspective from the occupational health and sustainable HRM literature (see
Figure 1).
The three-sample study fills gaps in occupational health, sustainable HRM, and stress literature, from the harm of work and COR perspectives, by demonstrating the bundle or synergistic effects of HHW, job tension, and SPS on employee well-being. Specifically, SPS manifests when a leader exercises subordinate-benefitting political influence to acquire and distribute resources and remove roadblocks impeding contributions and well-being [
13]. In terms of execution, the three-study element is essential to replicate the findings to gain greater confidence than single-study designs [
19]. First, an essential precondition to testing our hypothesised relationships is empirically confirming the distinctiveness of HHW from other study constructs. Hence, we used Sample 1 to test the measurement model to complement subsequent hypotheses testing. Second, in Samples 2 and 3, study hypotheses were tested to reveal consistency in findings across samples to gain greater confidence than single study designs.
This research makes multiple contributions. First, previous studies in the COR literature have used rest or recovery to manage employee engagement and burnout caused by loss cycles at work [
20]. Our study extends the COR literature to enhance our understanding of the human energy trough between resource loss and gain cycles at work due to the synergistic effects of antecedents on the well-being dimension of human sustainability. Thus, it contributes to empirical evidence for the ceiling effect of human energy to address Fritz, Lam, and Spreitzer’s [
10] theoretical proposition relating to “how people seek to manage their energy at work” (p. 36) for the benefit of management and business.
Second, the job demand-resources (JD-R) theory of work stress acknowledges the ceiling effect hypothesis of employee engagement for job performance from the individual employee-level perspective [
21]. However, we extend research by examining the ceiling effect of human energy from the organisation level in alignment with the institutional perspective of sustainable HRM to explore the interaction between SDG-8 and SDG-3. The ceiling effect maintains that unless organisations implement sustainable HRM characteristics, the human biological system cannot naturally replenish the energy depleted beyond the human energy trough job demands for performance and well-being [
22]. This view argues that organisational-level sustainable work-related strategies for SDG-8 are essential to understand the ceiling effect to help employees naturally reverse the human energy depleted at work to improve employee health and well-being (SDG-3). Finally, the study findings will prompt the practical implementation of organisational-level sustainable HRM practices to benefit employees and organisations. Results will facilitate job design with sustainability characteristics to minimise the synergistic effects imposed by work to improve myriad outcomes (i.e., commitment, extra-role behaviour, willingness to remain) in addition to satisfaction and performance.
6. Discussion
We conducted a three-sample study to investigate the three-way interaction or synergistic effect of HHW (PFPH, WRH, and SE), job tension, and SPS as an organisational resource on well-being as a work-related well-being dimension of human sustainability. Our study builds upon the earlier conceptualisation of all study variables to establish that these content domains are separate and distinct by using sample 1. A previous study from the sustainable HRM literature [
7] found that HHW and work recovery experience [
9] are two distinct constructs. The multiple confirmatory factor analysis in testing the study model (
Figure 1) using sample 1 extends the theory of harm of work from the sustainable HRM perspective demonstrating the benefit of considering HHW and job tension as two distinct constructs to understand the complementary effects of these variables on well-being.
The study findings extend empirical evidence of the complementary or cumulative effect of HHW and job tension on well-being as work characteristics for well-being. Previous studies [
54] explored the cumulative effects of job demand dimensions and job control on employee exhaustion and vigour (i.e., energy and enthusiasm) over time. They found that stable high job demand overtime contributes to increased exhaustion, and the group with increasing job control overtime experienced reduced exhaustion and increased vigour. Although in our study, the WRF and SE dimensions of HHW moderated the negative relationship between job tension and well-being in Samples 2 and 3, it was significant only in sample 3. Previous studies in occupational health and sustainable HRM literature revealed a direct relationship between high-performance work practices [
26,
55], work intensification [
39], and HHW. This study broadens empirical evidence from the occupational health and sustainable HRM perspectives by establishing the interaction effects of high job tension as adverse working conditions (SDG8) in facilitating the negative relationship between dimensions of HHW (i.e., WRH and SE) and employee well-being (SDG3) for the human dimension of sustainability at work.
There is no evidence of the envisaged negative complementarity effects between RFPH and job tension on well-being among both samples. Research methods on moderation study indicate that when there is a weak link between the independent variable and the outcome variable in the presence of a moderator, it is helpful to explore with an alternative/additional moderator or mediated moderation [
56]. Hence, the three-way interaction analysis in this study found that RFPH, high job tension, and high SPS curtail well-being, and it was consistent across Sample 2 and Sample 3. Similarly, the three-way interactions revealed that high SPS has a significant negative complementary effect of job tension and SE on well-being in sample 3. Still, the three-way interaction effect remained negative in sample 2 while not significant. These findings support the ceiling effect from the sustainable HRM perspective. The findings underscore the inadequacy of high SPS to help employees strive for resource gain to manage physical energy depleted during cumulative negative events of adverse working conditions (SDG-8) to buffer employee well-being (SDG-3).
6.1. Theoretical Contributions
This study is the first in the occupational health, sustainable HRM, and work stress literature exploring the complementarity of dimensions of HHW and job tension on well-being hypotheses. Our study provides empirical evidence to extend the attribution theory of harm of work, COR theory, and the ceiling effect of human energy theory from sustainable HRM for understanding the complementary adverse effects of HHW and job tension on well-being to plan organisational-level interventions for SDG-8 and SDG-3 to enhance human sustainability.
First, based on the attribution theory in the JD-R model, the strength of association between the attribution of the independent variable (i.e., work stressors) and outcome variables (e.g., well-being, employee turnover) was explained as a function of moderators [
57]. Similarly, the study findings contribute to the attribution of harm of work theory [
7]. As discussed earlier in the background section, the WRH, RFPF, and SE dimensions of HHW, used as independent variables, were developed based on stimulus-source attribution, manifestation or leading sign attribution, and causal attribution of the harm of work theory, respectively.
The study findings provide empirical evidence to the stimulus-source attribution perspective of harm of work theory in explaining that the function of WRH is negatively related to well-being when high job tension exists at work. When work restricts employees from being socially and physically reinvigorating activities for positive health, as a stimulus source for harm of work, it complements the negative effect of high job tension on employee well-being. Drawing from the causal attribution aspect of harm of work theory, the findings contribute to occupational health and sustainable HRM literature that the negative relationship between SE and well-being was buffered by high job tension at work. For example, work’s unintended adverse consequences or side effects on employee health, imposed by work practices while attempting to achieve organisational goals, negatively buffer well-being when high job tension is present.
Second, our study provides ample empirical evidence for understanding the complementary negative effects of each of the two dimensions of HHW (i.e., WRPF and SE) and high job tension on well-being. Furthermore, outlining the self-regulatory depletion mechanism of COR theory [
40], we explain that employees feeling of preoccupied and tired after a high level of human energy is depleted due to the complementary negative effect of each of the two dimensions of HHW (i.e., WRH and SE) and high job tension will buffer well-being. The intensity of the complementary negative effect of WRH and SE harm of work and high job tension was higher than the silo or isolated effect of these variables in curtailing employee well-being based on well-being.
Third, studies in JD-R and JD-C from the occupational health literature explore the three-way interaction effect of internal resources, job control, and job stressors on employee well-being and well-being [
58]. However, the synergistic or three-way interaction effect of HHW, job tension, and SPS on employee well-being is rare in the literature on occupational health, sustainable HRM, SDG, and job strain. Hence, to indicate how our study extends empirical evidence, we discuss previous studies about the two-way interaction effect of organisational resources, such as perceived organisational support [
59] and SPS [
13,
60], found to improve well-being during job tension experienced by employees. Similarly, the synthesis perspective of sustainable HRM studies on the two-way interaction of perceived organisational support buffers the negative effect of high-performance work practices on HHW [
27,
36,
55].
In expanding empirical evidence on previous three-way interaction and two-way interaction studies in the occupational health, job strain, and sustainable HRM literature, the current study suggests that high SPS does not represent the resource gain cycle of COR theory to buffer the negative complementarity between the two dimensions of HHW (RFPH and SE) and job tension on well-being. Hence, the findings extend the COR theory with empirical evidence for the ceiling effect of human energy theory from the occupational health and sustainable HRM perspectives [
11].
Fourth, the ceiling effect findings extend the temporal aspect [
18] of the cumulative adverse effects of working conditions on employee well-being for our improved understanding of human sustainability from sustainable HRM. Even with high SPS for employee resource gain, it is less likely to guard against resource depletion over a period due to cumulative adverse working conditions (SDG-8) to shorten the human energy trough. Shortening human energy trough between the resource depletion and gain cycles is vital to help employees allow their biological system to naturally reverse itself to gain human energy for future work performance and well-being. Hence, the findings will enable organisations to plan and develop socially responsible HR practices from the sustainable HRM perspective to facilitate employee well-being (SDG-3). Finally, this study provides empirical evidence for the ceiling effect of human energy to address Fritz, Lam, and Spreitzer’s [
10] theoretical proposition relating to “how people seek to manage their energy at work” (p. 36) for the benefit of management and business.
6.2. Limitations and Future Directions
Although this study has many strengths, including replicating and extending findings on the synergistic effect of study variables on well-being across three unique samples, it is not without limitations. We used convenience sampling to identify full-time employees for the three different samples in the study. Future studies should benefit from attempting to identify a representative sample of the larger group of full-time employee characteristics based on gender, age groups, and industry types. Despite controlling for similar constructs (i.e., HHW and job tension), and testing multiple models by conducting CFA to demonstrate the independence of study variables to explore well-being, furthering this effort will facilitate better conceptualising and developing theoretical space for organisations to understand subjective employee well-being to improve human sustainability.
A single cross-sectional, self-report data collection introduces common method bias (CMS) into the results. We used several procedural remedies indicated by Podsakoff et al. [
61] to mitigate the effects of CMB. For example, there is evidence that CMB does not create artificial interaction effects [
62]. Hence, CMB was not likely to affect the interaction effects reported in our findings. Finally, the hypotheses tested in this study used a multi-sample design to replicate the findings with a higher confidence level than the single-study designs [
19].
Future research would benefit from a longitudinal design to explore the dynamics of complementary and synergistic effects of HHW along with other employment practices (i.e., job design, work intensification) from the temporal perspective to understand the ceiling effect of human energy at work on job performance, employee engagement and human sustainability outcomes (i.e., employee health and well-being). This study’s results failed to support the envisaged synergistic effect of WRH on well-being. Hence, future research can also explore the indirect effect of prosocial job design on the cumulative conditional level of negative interactional effects of HHW and job tension using a mediated moderation study design [
63].
6.3. Practical Implications
Our findings promote sustainable HRM practices as an institutional or organisational response to the UN’s SDG-8 and SDG-3. Work intensification has become a dominant source that facilitates harm to work and job tension in increased absenteeism, presenteeism, and employee turnover and creates a competitive disadvantage to organisations and social costs to stakeholders [
6,
25]. Hence, the study results indicate that practitioners must note the complementary effect of HHW and job tension in reducing employee well-being, leading to a loss of human capital and competitive advantage. Hence, practitioners must re-think their management practices on SDG-8 (decent working conditions) while attempting to reduce the single negative effect of work that will improve well-being as a dimension of human sustainability (SDG-3).
In the occupational health and sustainable HRM literature, organisations cannot avoid imposing social costs of harm of work on employees while the organisation focuses on improved performance (i.e., profit). However, organisations also have a corporate social responsibility to minimise such harm of work imposed by adverse working conditions (SDG-8) on employee well-being (SDG-3). Practitioners know from the JD-R literature that adequate organisation resources will support employees to buffer well-being when employees experience high job tension [
60]. However, the synergistic effect results based on the ceiling effect of human energy theory highlight to practitioners that organisational resources provided to support employees to manage their depleted physical energy during cumulative negative events and adverse working conditions will have a limited buffering effect on employee well-being to retain human capital for competitive advantage. Furthermore, the findings revealed that it is essential for the board of companies and operational managers to become aware of the cumulative effect of HHW and job tension as adverse working conditions (SDG-8) to understand the ceiling effect of human energy to re-design jobs/roles to help employees naturally reverse the human energy depleted at work to improve employee health and well-being (SDG-3).
Finally, a literature review article revealed for practitioners that improvements in well-being and job performance are associated with a bundle of employment practices that includes job design which focuses on employee welfare [
2]. Hence, practitioners must consider re-designing jobs and roles with prosocial sustainability characteristics to facilitate decent working conditions (SDG-8). Subsequently, that will minimise the source of harmful effects of job stressors and harm of work in reducing employee well-being as a dimension (SDG-3) for human sustainability [
64]. For example, practitioners can facilitate employees to craft their job with prosocial sustainability characteristics, including motivational characteristics [
65], and be conscientious in minimising the negative effects of long-term exposure to tasks with extensive challenges and responsibilities for job holders.