**5. Conclusions**

This study contributes to the literature on occupational health, with an application for the public sector, especially the situation of municipal workers developing professional activities during the COVID-19 pandemic. It addressed the relationship between the multidimensional construct of burnout and QWL, by innovating in empirical assessment, considering both the isolated mediator of contribution to productivity and the joint mediator of the contribution to productivity and an appropriate salary.

In fact, the set of evidence presented outlines an important mediating role of not feeling contributive at work, as well as not being well paid, in the link between the burnout syndrome dimension of low effectiveness and QWL. These findings shed new light on the need for public managers in leading roles, as well as human resource departments in the public sector, to design innovative incentives, appropriate measures, and work schedules to counterbalance such tendencies.

Regarding implications for public authorities, and based on our previous direct contacts and auscultation in the context of online training delivered to municipal workers, in order to address the negative association between the three burnout dimensions: emotional exhaustion, feelings of cynicism, and feeling less effective, and the motivating and economic mediators: contribution to productivity and appropriate salary; progressive remuneration mechanisms should be created, including a (fixed) basic salary and a (variable) supplementary salary indexed to productivity goals, and aligned with a new production and evaluation framework, to be implemented in public administration. Also taking into consideration the results of brainstorming, co-creation, and open innovation groups dynamics promoted in the previously referred online training delivered to municipal workers, further action is required to promote occupational health, QWL, and gender equality in public administration, aiming to diminish income inequality and foster the work–life balance of both female and male public servants.

Adding to the above, and considering the previous experience and project-based and organization innovation views of the authors collected in the previous exercise of public administration roles, it is suggested that public managers adopt innovative organizational practices, including flexible work schedules; project management practices; work innovation labs; mindfulness programs; hybrid work formats; and special incentives for workers with families, including children at school and older people with special needs, in order to tackle the negative associations and mediating effects found in the current study.

Despite the important set of discoveries made in the course of the current study, it is not free of limitations that should be considered in future research. Firstly, this study uses a cross-sectional online survey, which might have limited access by municipal workers who are less familiar with the internet or less likely to use it, for instance, manual workers rather than office workers. The convenience sampling procedure was obtained by direct contact with chief positions (middle managers) in the municipalities during online training courses, something that could bias access by some groups or individuals. This is a non-probability sampling method wherein units are selected for inclusion in the sample because they are the easiest for the researcher to access. The use of this non-random sampling can be due to availability at a given time or willingness to participate in the research, as occurred in the context of the previously referred online training.

One limitation associated with the empirical test of the convenience sample is that mixing functions and qualifications of municipal workers could bias the results, making it impossible to focus on one category of municipal workers. Nevertheless, bearing in mind the sample's dimension and the observed diversified set of institutional roles, it was found to be advantageous to consider municipal workers with leadership roles, as well as qualified and non-qualified workers.

It is also worthwhile to outline that the limited sample size was confined to Portuguese municipalities and, therefore, these results cannot be generalized to municipalities in other countries. Another aspect associated with the representativeness is the fact that the sample is related only to public municipalities, excluding from the study other public municipal firms. Therefore, representativeness is limited, and the results of the study cannot be generalized to the entire Portuguese municipal system, including the entrepreneurial units with the participation of municipal bodies.

The study was carried out during a five-month period, during a pandemic, which corresponded to one lockdown and then the relaxation of some lockdown measures. Furthermore, the inexistence of data gathered before the pandemic means comparisons cannot be made. Future studies could focus on participants who already felt burnout symptoms before the COVID-19 pandemic, to examine the increase, maintenance, or decrease of symptoms during the pandemic. When gathering information through a questionnaire, bias can appear linked to the tendency to present a favorable image of oneself. This tendency could be increased as sending the invitations to the leading positions inside the institutions can also produce a biased collection. In the sample used, 26% have leadership positions and 65% were qualified workers, while only 8% were non-qualified workers.

Future research endeavors on the relationship between burnout and QWL should perform a comparative analysis of different hierarchical positions, for different activities in the public sector, in order to assess the mediating effects of the contribution to productivity and appropriate salary, considering different cohorts of remuneration, education, and age.

**Author Contributions:** Conceptualization, D.P., J.L. and L.R.; validation, J.L.; estimation, D.P. and J.L.; data curation, D.P.; writing—original draft preparation, D.P.; writing—review and editing, D.P., J.L. and L.R; supervision, J.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** The Portuguese Foundation for Science and Technology (Grants and NECE- UIDB/04630/ 2020) provided financial support for this study.

**Institutional Review Board Statement:** Ethical review and approval were waived for the study on human participants in accordance with the European legislation and institutional requirements applicable in this study, which was not conducted in our own higher education institution. The study was funded in the scope of the R.E.NewAL. SKILLS project (Project Number: 591861-EPP-1-2017-1-IT-EPPKA2-SSA) and the board governance structure of this project established a quality assurance, evaluation, and monitoring framework, through which the R.E.NewAL. SKILLS Contents Quality Plan (REC-QP) was created to ensure defined and shared quality standards for the contents production, including the questionnaires for gathering data, as well as identifying key roles among partner representatives and scores to be achieved by the contents produced. This plan created a set of committees to ensure ethical procedures, quality control, efficiency, and monitoring: a General Assembly, the ultimate decision-making body of the consortium and supervisory body for the execution of the project, coordinated by a representative of the Lead Partner (Coordinator of the General Assembly) acting as chairperson; and a Curriculum Committee (CC) made of RENewAL Contents Quality Managers (CQMs), selected by partner organizations among their staff, responsible for the quality control of R.E.NewAL. SKILLS contents, such as the survey questionnaire. The design of the questionnaire and methodology used to collect data was approved by the General Assembly, the partners, and the CC, assuring that the methods of data collection, the conformity of the questionnaires, and the subsequent anonymized treatment complied with ethical and quality standards, with published results not containing any entity-identifying information. Finally, the Education, Audio visual and Culture Executive Agency (EACEA) approved the outputs of the R.E.NewAL. SKILLS and closed the project with success.

**Informed Consent Statement:** Informed written consent was obtained from all subjects involved in the study.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** All the authors acknowledge the highly valuable comments and suggestions provided by the editors and reviewers, which contributed to improving the clarity, focus, contribution, and scientific soundness of the current study. The study was conducted with the support of FEFAL-Portuguese Foundation for the Studies and Training of Municipalities, which made possible the administration of the survey in a sample of 459 municipal workers.

**Conflicts of Interest:** The authors declare no conflict of interest.
