The R2 Puzzle

Previous research has argued that the degree of co-movement of stock returns (the R² of a market regression) at country-level can be explained by the interaction of firmspecific and market-wide information. The R² measure has been used to investigate a number of issues of potentially great importance to accounting, such as whether countries with poor corporate governance regimes and weak legal protection of private property rights are more likely to have poor information environments or to assess the informativeness of prices. To date, only limited research has been carried out to assess the reliability of an information interpretation of the R² measure at a firm-level within a country rather than at an aggregate country level. In this paper we now examine the properties of stock returns co-movement at the firm-level within two countries, UK and USA, thereby being able to filter out certain extraneous factors that could arise in cross-country settings. We analyse the performance of this overall measure by triangulating it with other information-related measures which previous research has suggested capture partial aspects of the information environment. We find some serious flaws in the methodology and our findings suggest that when using it at firm-level, it may be being driven by other factors related to uninformed trading.Information; R²; firm-specific information; market-wide information; volatility; disclosures; comovement

The use of the R2 as a measure of firm-specific information: A cross-country critique

Recent research uses the degree of stock returns co-movement as a measure of the quality of a country’s information environment. It has been argued that stronger property rights, better corporate governance regimes and more efficient enforcement mechanisms lead to prices incorporating more firm-specific information and, therefore, co-moving less with the market. In this paper, we use a much more comprehensive international data set than in prior research, encompassing forty countries over twenty years, to evaluate the reliability of this approach in a crosscountry setting and to analyse the behaviour of the measure used. Our results demonstrate severe limitations in the use of co-movement as measure of information quality. We highlight the instability of the measure and show that it can produce results that are often difficult to reconcile with such an informational explanation.Information; R²; firm-specific information; market-wide information; volatility; disclosures; co-movement; cross-country information environment

Cross-Border Information Transfers: Evidence from Profit Warnings Issued by European Firms

This paper reports evidence on cross-border accounting information transfers associated with profit warning announcements. Using a sample of firms from 29 European countries, we find that negative earnings surprises disclosed by firms in one country affect investors’ perceptions of comparable nonannouncing firms in other countries. The form and magnitude of cross-border effects is consistent with domestic transfers. Tests explaining variation in cross-border information transfers provide some (albeit rather limited) evidence that effects vary according to a range of firm-, industry- and country-level characteristics.Information transfers; Profit warnings

Agentes tutor e estilos de aprendizagem em ambientes adaptativos

O Processo de Bolonha que pretende mudar o paradigma educativo passando a estar centrado no aluno, é um dos maiores desafios que o ensino superior enfrenta actualmente. Deste modo, constatando-se que a maioria das plataformas de e-learning são usadas como simples repositórios de conteúdos, pretende-se, através de uma abordagem baseada em actividades de aprendizagem, incentivar a mudança do processo educativo. Neste artigo é focada a importância das actividades de aprendizagem e o papel dos agentes tutor no apoio ao aluno, adaptando o ambiente de aprendizagem, detectando dificuldades e dando sugestões de recursos que reforcem os conhecimentos. A adaptação é feita com base no estilo de aprendizagem do aluno, o seu ritmo e o nivel de colaboração no processo educativo

Advances in Artificial Intelligence to Model Student-Centred VLEs

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Experimental assessment of RRM techniques in 5 GHz dense WiFi networks using REMs

“© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”The increasing acceptance of WiFi has created unprecedented levels of congestion in the unlicensed frequency bands, especially in densely populated areas. This results mainly because of the unmanaged interference and uncoordinated op- eration between WiFi access points. Radio Environment Maps (REM) have been suggested as a support for coordination strategies that optimize the overall WiFi network performance. In this context, the main objective of this experiment is to assess the benefit of a coordinated management of radio resources in dense WiFi networks at 5 GHz band, using REMs for indoor scenarios. It was shown that REMs can detect the presence of interfering links on the network or coverage holes, and a suitable coordination strategy can use this information to reconfigure Access Points (AP) channel assignment and re-establish the client connection, at a cost of diminishing the aggregate throughput of the network. The technique of AP hand-off was tested to balance the load from one AP to another. Using REMs, the Radio Resource Management (RRM) strategy could reconfigure the network to optimize the client distribution among available APs. Although the aggregate throughput is lower after load balancing, the RRM could increase the throughput of the overloaded AP.info:eu-repo/semantics/publishedVersio

Cash holdings around the world: The Financial crisis, culture and shareholder rights.

The goal of this paper is to study how cash holdings were affected by the 2008 financial crisis. Our results suggest that the 2008 financial crisis had a negative impact on cash holdings. However, the impact depends on the post crisis period. Although from 2008 to 2014 the impact was negative, from 2009 to 2010, the impact was positive. This result shows that after the crisis, firms did not need to hold cash to cover eventual shortfalls. Precautionary motives no longer can hold as the main explanatory theory, which brings about another hypothesis, namely the agency hypothesis, for explaining firms’ cash holdings. We also have shown that in collectivistic countries, firms’ cash holdings present higher reductions, meaning that they tolerate higher levels of risk. We suspect that this is a result of the unprecedented values in terms of cash holdings until 2008