Adelino Fortunato

Desde a sua criação em 2010 na eletricidade e em 2011 no gás natural, para combater os efeitos da Crise Financeira Global de 2008‑2009, a tarifa social de energia em Portugal sofreu adaptações no sentido do alargamento do leque de beneficiários. Ainda que subsistam detalhes que podem vir a ser melhorados, a introdução da automaticidade no acesso ao benefício em 2016 revelou‑se uma alavanca poderosa para alargar o âmbito de famílias contempladas e para explicar o sucesso dos seus impactos. Tendo em conta o balanço desta experiência, procuramos neste artigo usar a pertinência dos seus princípios para recomendar a extensão da tarifa social aos setores das águas, telecomunicações e transportes, no contexto da crise social e económica gerada pela pandemia Covid‑19.

The aim of this work is to analyse the behaviour of agents in highly concentrated and strongly regulated electricity wholesale markets with rigid demand. In order to accomplish this aim, the analysis was based on the former Spanish electricity generation market, between January 1999 and June 2007, before the MIBEL (Iberian Electricity Market) has started. The analysis is carried out in the theoretical framework of the structural models. Despite the characteristics of this market, the paper suggests that the average high markups observed in the period examined were very likely due to the implementation of anti-competitive strategies. Therefore, the analysis carried out shows that the opening of a wholesale electricity market without the prior increase in the number of market players does not prevent, by itself, the manipulation of the market, even when the market is strongly regulated.

The existence of market power in the Iberian electricity market is well known. The measurement and the understanding of market power practices in the Iberian electricity market turn out to be very interesting considering the particular case of Portuguese and Spanish markets, where two antagonistic factors remain active: liberalization and the strong, direct government intervention. For various reasons, among which the difficulty in obtaining the data stands out, market power in the Iberian electricity market has rarely been measured. This work aims to contribute to a better knowledge of the way the market power occurs in the Iberian electricity market, applying a particular methodology to determine the market power, highlighted by the works of Frank Wolak in the electricity sector. Our work analyzes the results obtained in the light of the evolution of the electricity sector during the analyzed period.

A residential water demand equation is estimated using a panel data sample of five Portuguese local communities and 72 months, corresponding to a total number of 360 observations. Because of the presence of multi-part tariffs, we use the two common price-related variables: marginal price and difference as explanatory variables. To prevent the simultaneity bias from using observed quantities to determine the values of marginal price and difference directly from the rate schedule, we use an instrumental variable approach to create a constant marginal price and difference parameters for each rate structure. The price elasticity values obtained fall within the range of those found in other case studies. Thus, although presenting weak elasticity, price seems to play a role in water demand management. However, we do not confirm the expected influence of difference on residential water demand. This can be a consequence of the complexity of the Portuguese water tariffs and the confusing signs that come from the simultaneous use of fixed quotas and increasing block tariffs. So, it is imperative to clarify water tariffs objectives by reviewing the Portuguese water tariffs design processes.