Revista Galega de Economía

The week-of-the-year effect and the Adaptive Markets Hypothesis: Evidence from a new database

Júlio Lobão — 2022-11-21

In this paper, for the first time, we study the calendar anomaly called “the week-of-the-year effect” in the Portuguese stock market. The week-of-the year effect was originally identified by Levy and Yagil (2012) and refers to the occurrence of significantly different market returns during certain weeks of the year. The sample used was built from a new historical database covering about 120 years of the Portuguese stock market. It was found that the first and last weeks of the year generated significantly higher returns than the other weeks of the year. Furthermore, a subsample analysis reveals that the week-of-the year effect has evolved over time. In general, our results suggest that the Adaptive Markets Hypothesis provides a better explanation for the dynamics of the Portuguese stock market.

How zombie firms affect healthy firms: The case of Portuguese trade sector

Armando da Silva — 2022-11-14

Zombie companies can be classified as being nonprofitable, having low productivity and being ten years old or over; these businesses continue to exist due to the support of banks and governments. This paper aims to understand the impact of these types of firms on the investment, employment growth and labour productivity of healthy companies from the wholesale and retail trade and the hospitality sector during the period 2011-2018. The data obtained indicate that the prevalence of zombie companies in Portugal (in the sectors under study) is higher in periods of economic crisis and that most of them are old and large companies, especially in the hotel industry sector. By using panel data models with fixed effects, our investigation concludes that zombie firms negatively affect how healthy companies are run, because they reduce the latter’s investment expenditure and workforce productivity.

The Effect of Storytelling Associated with COVID-19 on Engagement

Anabela Ribeiro — 2022-11-30

The main objective of this investigation is to understand how the posts in form of stories published by brands associated with the COVID-19 pandemic affected engagement with their consumers. Regarding the stories, plot, characters and verisimilitude have been evaluated. With regard to consumer engagement (CE), affective, emotional and cognitive involvement have been assessed. This study uses a qualitative methodology with a netnographic approach that takes into account the comments of the advertisements published on two social networks, Facebook and Instagram, by nine Portuguese brands. The results of this research reveal that in order for the stories associated with COVID-19 to have a greater level of influence on the customer, they must use their elements as a whole, to encourage positive consumer engagement.

The use of transfer entropy to analyse the comovements of European Union stock markets: a dynamical analysis in times of crises

Paulo Ferreira — 2022-11-24

Understanding the linkages among stock markets holds great importance for investors, policymakers and portfolio managers. When considering the integration of international stock markets and given they are complex systems, it is important to understand how they are related and how they influence each other. Studying data from 25 European Union stock market indices, this piece of research aims to evaluate the dynamics of influence among them. In terms of method, a non-linear approach has been applied, based on transfer entropy with static and dynamic analysis. As the main finding, a strongly influential relationship between some indices should be highlighted. The static analysis allows us to infer that central and western European Union countries are the main influencers, while the dynamic analysis leads us to the conclusion that the relationships between the stock markets have changed over time, revealing their dynamism. The results obtained have several implications. For instance, for investors and portfolio managers, the information about comovements is relevant for diversification purposes and for their decisions on where to make their investments, build portfolio strategies and manage risks; however, for policymakers, the constant monitoring of stock markets may detect increases in the connection between markets, which could be understood as signs of instability.

Acknowledgement of reviewers for 2022

Maria Luisa Chas-Amil — 2022-11-30