Abstract
Resumo Este estudo visa a identificar como mecanismos de controle externo e interno da governança corporativa, tipicamente considerados no setor empresarial privado, são aplicados ou transformados para o setor público nas empresas estatais. A partir de uma revisão do problema de agência e dos mecanismos propostos para sua mitigação no contexto empresarial, este estudo analisa a situação da governança das empresas estatais no Brasil e em Portugal, com vistas a comparar as soluções adotadas nos dois países e as necessidades de desenvolvimento. Além de compartilhar histórias e fundamentos culturais comuns, esses países são caracterizados como ambientes de pouca segurança aos investidores e fragilidade de instrumentos de solução de litígios, por estruturas de propriedade concentradas e por mercados de capitais ainda insuficientes para pressionar o comportamento das empresas, condições que fragilizam os mecanismos de mercado de controle externo e amplificam a influência das peculiaridades das questões internas de governança das estatais. As análises apontam significativas evoluções recentes nas práticas de governança das estatais, mas identificam desafios que ainda precisam ser direcionados.

Abstract
An exchange-traded fund (ETF) is a marketable security that tracks a stock index, a commodity, bonds, or a basket of assets. Therefore, returns of ETFs that track a benchmark index portfolio should mimic the returns of their benchmark indexes. If a benchmark index's performance exhibits a seasonal pattern, then the performance of its associated ETF should replicate that pattern. This type of ETF performance seasonality is induced by trends in the market of securities in the benchmark index portfolio. Any other seasonality can be considered to be idiosyncratic. Based on a sample of 148 ETFs listed in NYSE Arca, this article provides evidence of a half-year effect (higher performance in the first half-year), a quarter effect (outperformance of the second quarter and underperformance of the fourth quarter), and month within the quarter effect (higher and lower performance in the first and third months of each quarter, respectively). Additionally, superior and inferior performance were observed in April and December, respectively. These seasonal patterns are not visible on benchmark indexes, with the exception of the unusually positive performance in April, which can be considered induced seasonality. The other effects, which cannot be attributed to underlying markets, are evidence of idiosyncratic seasonality.

Abstract
There are two recognized tendencies in electricity markets: the development of spot markets and the increase of renewable electricity generation. These tendencies create dynamics in both price and volatility. In Portugal, there are powerful support schemes for renewable electricity. Therefore, the main sources for generating electricity in Portugal are renewable. This paper analyzes ex-post the impact of energy produced in special regime on the wholesale hourly spot market prices of Portuguese electricity during the period 2009-2016. It finds that special regime generation has a negative impact on the wholesale price. Effectively, an increase of special regime generation by 1.0 GWh, all else being equal, reduces the wholesale spot price by 3.9 (sic)/MWh. This represents 8.6% of the average wholesale price. Moreover, the substitution of 1.0 GWh of coal generation for special regime sources has an impact on electricity spot prices of, on average, -15.96 (sic)/MWh. This paper also concludes that using special regime generation to supply the future growth of demand will decrease wholesale electricity spot prices more intensively than using other technologies.

Abstract
The business models of banks are often seen as the result of a variety of simultaneously determined managerial choices, such as those regarding the types of activities, funding sources, level of diversification, and size. Moreover, owing to the fuzziness of data and the possibility that some banks may combine features of different business models, the use of hard clustering methods has often led to poorly identified business models. In this paper we propose a framework to deal with these challenges based on an ensemble of three unsupervised clustering methods to identify banking business models: fuzzy c-means (which allows us to handle fuzzy clustering), self-organizing maps (which yield intuitive visual representations of the clusters), and partitioning around medoids (which circumvents the presence of data outliers). We set up our analysis in the context of the European banking sector, which has seen its regulators increasingly focused on examining the business models of supervised entities in the aftermath of the twin financial crises. In our empirical application, we find evidence of four distinct banking business models and further distinguish between banks with a clearly defined business model (core banks) and others (non-core banks), as well as banks with a stable business model over time (persistent banks) and others (non-persistent banks). Our proposed framework performs well under several robustness checks related with the sample, clustering methods, and variables used.

Abstract
The first Portuguese corporate governance code was issued by the Portuguese Securities Commission (CMVM) in 1999. This code has been revised every two years. More recently, in 2006 the civil society issued a code of good governance as well. In this paper we argue that the issuance of codes of good governance in Portugal has been very important for two reasons. First, it has been leading the discussion on corporate governance matters. Second, it has induced the evolution of the governance system both by inspiring the enacting of rules and regulations, and by influencing the existing practices. We show that the level of the companies' compliance with the good governance code has been increasing, which means that companies have been changing their practices. Furthermore, large and more liquid companies are more likely to comply with the recommendations. We conclude that the "one size fits all" model is not appropriate for the Portuguese case, and that the good governance code should account for size and liquidity. On the other hand, assuming that the best practice code is specially designed for large companies, it is expectable that smallest companies rely more intensively on the "explain" prerogative of the "comply or explain" principle than the biggest companies.

Abstract
Several supervisory authorities and governmental working groups issued corporate governance best practice codes for listed companies during the nineties. In this paper, we used a unique database that allowed us to analyse the relationship between the level of compliance of the code of best practice issued by the Portuguese Securities Market Commission and the returns of the concerned companies. By using a multifactor model, one can conclude that there is a positive relationship between the compliance of some of these recommendations and the returns that were determined. The recommendations on the structure and functioning of the executive board deserve a special attention. However, globally, CMVM's code of best practice doesn't have a systematic effect on firm returns.