Browsing by Issue Date, starting with "2019-07-01"
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- The impact of time shifting on TV consumption and ad viewershipPublication . Belo, Rodrigo; Ferreira, Pedro; Matos, Miguel Godinho de; Reis, FilipaIn this paper we study the impact of time shifting on TV consumption and ad viewership. We analyze the results of a field experiment in which a random sample of “triple-play” households were given a set of premium TV channels broadcasting popular movies and TV shows without commercial breaks. A random subset of these households were given access to these channels with time shifting (automated cloud recording for later viewing or rewinding of broadcasted programs), while the remainder were not. This design allowed us to identify the effects of time shifting on TV consumption. On average, we found that receiving access to the channels with time shifting increased total TV consumption because it increased time-shifted viewership while leaving live viewership unchanged. The increase in the live viewership of these channels was similar to the reduction in the live viewership of the originally available channels, resulting in a net zero effect on live viewership. It appears that time shifting does not change the concentration of live viewership, but it does increase the concentration of total TV viewership, because it is used disproportionately to watch the most popular programs. Finally, we found that time shifting does not change the likelihood of skipping ads during live viewership, suggesting that households do not use time shifting to strategically avoid ads.
- Is liquidity the missing piece in asset-pricing models?Publication . Marotta, Pasquale; Faias, José Afonso de Carvalho TavaresLiquidity is usually defined as the easiness of trading an asset. Despite this fairly simple definition, many measures have been proposed throughout the years but none of them have ever received a general consensus, thus leading to different results regarding the effects of liquidity on stock returns. By adopting three commonly used proxies (the relative bid-ask spread, the proportion of daily zero returns and the turnover rate), this study attempts to identify how and if liquidity has any explanatory power of the cross-sectional variability of returns. Moreover, the study also analyzes different investment strategies based on liquidity, with the goal of understanding whether or not liquidity can also outperform market returns. Results confirm the idea that liquidity can, indeed, affect stock returns, but this is not true for all proxies. Additionally, liquidity appears to be a profitable investment style that allows investors to obtain extra-returns by also containing the riskiness of the portfolio and the transaction costs associated with the strategy.
- Business culture and corporate social responsibility: an analysis in the light of catholic social teaching with an application to whistle-blowingPublication . Alves, André Azevedo; Booth, Philip; Fryzel, Barbara
- Proximity payments : drivers and barriers of NFC MPs in Portugal : exploratory researchPublication . Kozachenko, Oleksandr; Rita, Miguel FontesThe dissertation is focused on understanding perception of Portuguese users of Near Field Communication mobile payment systems existing on the market since 2015. NFC MPs have been created to enhance customer experience, increase speed of payment process and ensure higher trust in providers. Being a relatively new system, NFC MPs are not widely spread and are not fully understood by prospected users. Such affects acceptance speed and rate at which the system is adopted by users and providers. In order to analyze the challenges faced by NFC MPs, in-depth interviews were held, followed by an online study conducted next to a pool of 144 respondents. The study has shown that there is existing awareness on the market of NFC MPs, nevertheless there is very low usage rate. Most important barriers to adoption are low understanding of benefits of using the system and low understanding of the process behind the payment system. High perceived fees and risks are likely to prevent adoption on the market. On the other hand, perceived benefits of the systems are ease of use, convenience, having the technology in hand and secure transactions which serve as driver to adoption. There is existing interest on the Portuguese market in NFC MPs which exists mostly amongst the age category of 21 to 25 years.
- Default determinants of PE-backed firms in EuropePublication . March, Giulia; Reis, Ricardo César Ribeiro Ventura FerreiraThis study examines a sample of European private equity transactions undertaken between 2000 and 2015. The factors that have an impact on the likelihood of the target’s default are identified and evaluated through a logistic regression. Three groups of variables are included in the analysis: (1) economic variables which capture the trend of the overall economy; (2) deal features, defined as variables on which the PE has a decisional power; (3) specific characteristics of the target firm before the transaction. The findings suggest that leverage employed in the transaction, cross border deals, targets ROA previous to the transaction, and the fact of being a company from UK has an impact of the likelihood of default
- Valorization of natural extracts as potential enzymatic browning inhibitors in processed fruitsPublication . Dias, Cindy; Amaro, Ana L.; Fonseca, Alexandre; Rocha, Sílvia M.; Silvestre, Armando; Isidoro, Nelson; Pintado, Manuela
- Ética da modernidade crítica : apontamentos bibliográficos sobre a obra de Adela CortinaPublication . Abrunhosa, Ricardo Pereira; Costa, José Miguel Stadler Dias
- Utilização do internamento hospitalar em Portugal continental por crianças com doenças crónicas complexas (2011–2015)Publication . Lacerda, Ana Forjaz; Oliveira, Graça; Cancelinha, Cândida; Lopes, SílviaIntrodução: Fruto da mudança epidemiológica, o interesse pelas doenças crónicas complexas no sistema de saúde pediátrico tem vindo a crescer. Assim, pretendemos avaliar a utilização do internamento hospitalar do Serviço Nacional de Saúde (Portugal Continental) por doentes pediátricos (0 – 17 anos) com doenças crónicas complexas. Material e Métodos: Estudo epidemiológico observacional longitudinal retrospetivo (base de dados de morbilidade hospitalar anonimizada). Selecionámos episódios de internamento de doentes pediátricos, entre 2011 – 2015; excluímos recém-nascidos saudáveis e radioterapia ambulatória. Análise descritiva dos episódios de internamento de doentes pediátricos com doenças crónicas complexas, caracterizados por número e categoria de doenças crónicas complexas. Foram aplicados testes não paramétricos à duração de internamento, despesa e mortalidade. Resultados: Nos 419 927 episódios, constavam códigos de doenças crónicas complexas em 64 918 (15,5%). Estes episódios com doenças crónicas complexas representaram 29,8% dos dias de internamento, 39,4% da despesa e 87,2% dos óbitos. Custaram o dobro dos episódios sem doenças crónicas complexas (€1467 vs €745) e tiveram uma mortalidade 40 vezes superior (2,4% vs 0,06%). Do total, 46,0% foram programados (sem doenças crónicas complexas 23,2%); 64,8% ocorreram em hospitais grupo III – IV (sem doenças crónicas complexas 27,1%). Nos episódios com doenças crónicas complexas, a doença maligna foi a categoria mais frequente (23,0%); a maior demora mediana (12 dias, 6 – 41), despesa mediana (€3568,929 – 24 602) e mortalidade (13,4%) verificaram-se na categoria neonatais. Discussão: Esta análise mostrou que, embora o número absoluto de internamentos de doentes pediátricos esteja a diminuir em Portugal Continental, à semelhança de outros países desenvolvidos, os internamentos com doenças crónicas complexas têm vindo a aumentar proporcionalmente, sendo mais prolongados, onerosos e com maior probabilidade de morte do que os episódios sem doenças crónicas complexas (tendências acentuadas quando constam duas ou mais doenças crónicas complexas). Conclusão: As doenças crónicas complexas são relevantes na atividade e despesa do internamento hospitalar pediátrico em Portugal Continental. Este reconhecimento e a integração de cuidados paliativos pediátricos desde o diagnóstico são essenciais para adequar a utilização do hospital, desenvolvendo alternativas efetivas e sustentáveis que vão ao encontro das necessidades das crianças, famílias e profissionais
- Can we anticipate the stock market using the put-call parity? : a study on return predictabilityPublication . Gomes, Ana Sofia Moreira; Kokkonen, Joni AleksiUsing the deviations from the put-call parity, we investigate the existence of relevant information about the future stock price not yet incorporated in the stock market. In order to capture the extent of the mispricing between pairs of calls and puts’ options, we calculate daily volatility spreads as the weighted average of the difference between implied volatilities. We use the option signals provided by our measure to create stock portfolios, assessing the informational flow between the two markets. We find a strong evidence that relatively expensive calls in respect to puts carry more information about future stock returns than the opposite: the hedge portfolio earns a four-week abnormal return of 31.6 bps. We further extend our research to study the effect of liquidity and informed trading. Our results suggest that the most liquid options are the ones conveying more information about future stock returns. Furthermore, informed trading is only relevant when its probability in the stock market assumes high values. Finally, we show an increase of returns’ predictability in the post-financial crisis period, which contradicts the argument present in literature that this flow would tend to disappear due to the learning process of the market participants. Overall, we provide evidence on return predictability by the incorporation in the stock market of information intrinsic to the deviations from put-call parity.
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