Elisabete Neves

With the globalization and internationalization of markets, companies need to be more competitive and offer high-quality guarantees to consumers, suppliers, banking institutions, and shareholders. Thus, the objective of this paper is to measure the impacts that these guarantees, analyzed through quality management, environmental management, and management of occupational health and safety standards, will have on the return on assets (ROA) of companies classified by sector of activity, considering each of the certifications individually and as a whole. The panel data approach methodology was used for 10 years in Portuguese-certified companies between 2010 and 2019. The Chow test, the Breusch-Pagan, and the Hausman test were applied to identify a more feasible model between the pooled OLS and the random or fixed effects model. Furthermore, the cluster-robust standard errors model was applied.
The results show the existence of synergies when adopting more than one certification to improve firm performance. Moreover, the single certification estimate by sector results are significant and can be positive drivers of profitability, but only for companies in the manufacturing industries related to natural resources. However, they trigger negative results in the accommodation, catering, and information and communication sectors.

Acknowledgment
This paper is funded by National Funds through the FCT – Foundation for Science and Technology, I.P., within the scope of the project Refª UIDB/05583/2020. Furthermore, we would like to thank the Research Centre in Digital Services (CISeD) and the Instituto Politécnico de Viseu, for their support.