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- Long-term dependence in financial prices: evidence from the Belgian stock market returnsPublication . Gomes, LuísThis article aims to contribute to the discussion of long-term dependence, focusing on the behavior of the main Belgian stock index. Non-parametric analyzes of the general characteristics of temporal frequency show that daily returns are non-ergodic and non-stationary. Therefore, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA), under the fractional Brownian motion approach, and we found slight evidence of long-term dependence. These results refute the random walk hypothesis with i.i.d. increments, which is the basis of the EMH in its weak form, and call into question some theoretical modeling of asset pricing. Other more localized complementary study, to identify the evolution of the degree of dependence over time windows, showed that the index has become less persistent from 2010. This may mean a maturing market by the extension of the effects of current financial crisis.
- Explanatory Factors of the Capital StructurePublication . Silva, Marta; Gomes, Luís; Lopes, Isabel CristinaThis paper presents an empirical study of the capital structure of Portuguese companies where the main objective is to find key explanatory factors for indebtedness decisions. The relations between indebtedness and its determinants are tested in the light of the Trade-Off Theory and the Pecking-Order Theory. The motivation of this work was to contribute to the scientific research on the influential determinants of the capital structure and to deepen the knowledge of the Portuguese market. The quantitative methodology is used, through an econometric model for panel data using accounting information of 55 Portuguese companies between 2014 and 2016. Statistical tests such as the F test, the Lagrange Multiplier Breusch-Pagan test and the Hausman test were used to identify the most appropriate method of estimation, which resulted in a panel data model with random effects for individuals. The findings of this study suggest that indebtedness have a positive relation with tangibility and the size of the company, which supports the Trade-Off Theory. However, the positive relationship with the non-debt tax benefits suggests the importance of taxes, contrary to Trade-Off Theory. The negative relationship with cash flows, coupled with the positive relationships between size and growth opportunities, suggest the use of funding only when internal funds become insufficient, supporting the Pecking-Order Theory. The general results support that both theories partially explain the financing decisions of Portuguese companies.
- Long-term memory in financial prices: evidence from the Dutch stock market returnsPublication . Gomes, Luís; Soares, Vasco J. S.; Gama, Sílvio M. A.; Matos, José A. O.The purpose of this paper is to contribute to the discussion of long-term memory, focusing on the behavior of the main Dutch stock index.The analysis of the general characteristics of temporal frequency reveals that daily returns are non-ergodic, non-stationary and non-independent. Consequently, we have employed the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA), under the fractional Brownian motion approach, and found slight evidence of long-term persistence. This suggests that this market is more prone to predictability ("Joseph effect"), but also trends that may be unexpectedly disrupted by discontinuities ("Noah effect"). Although the evidence of fractal dynamics has weak support, refutes the hypothesis of random walk with i.i.d. increments. This implies that the use of statistical limit arguments to determine conventional financial statistics, as used in the Capital Asset Pricing Model and option valuation models, is scientifically incorrect. Furthermore, a more localized (in time) study to identify the evolution of the degree of long-term memory over time showed a change in the characteristic index from persistent to anti-persistent, more evident after 2010. This suggests that the AEX market does not correspond to Efficient Market Hypotheis in strictly sense of Fama (1970), although it has progressed closer to this theoretical ideal during the worsening of the current international financial crisis.
- Assessment and students alignment: the case of a portuguese business simulation coursePublication . Costa Oliveira, Helena; Gomes, LuísIn high education, assessment components are very important as condition the student’s success. Such components must involve several issues including soft and hard skills. The quality of education will depend on the alignment of such skill and their assimilation by students. We present a course taught in Portuguese, belonging to the graduation of Accounting and Administration, that covers several assessment tasks such as oral presentation, written exams, operationalization of tasks, assessment of physical dossiers, punctuality and attendance, ethical behaviour, and company management report. Data were collected in 2019 thought to triangulate methods, namely documental analyses, direct observation, and paper questionnaires. We aim to evaluate the degree of importance perceived by students for each evaluation component. We conclude that the students consider all of the components very important, attributing less importance to hard skills, namely the multidisciplinary contents evaluated thought written exams. This paper contributes to higher education studies by presenting the alignment of an assessment model and students.
- Financial Contagion from the Subprime Crisis: A Copula ApproachPublication . Mendes, Rita I.L.; Gomes, Luís; Ramos, PatríciaThe magnitude of the subprime crisis effects caused recessions in several economies, giving rise to the global financial crisis. The scale of this major shock and the different recovery profiles of European economies motivated this paper. The main objective is to look for evidence of contagion between the North American financial market (S&P500) and the financial markets of Portugal (PSI20), Spain (IBEX35), Greece (ATHEX) and Italy (FTSEMIB), in the South of Europe, and the financial markets of Sweden (OMXS30), Denmark (OMX2C0), Finland (OMXH25) and Norway (OsloOBX), in the North of Europe. Considering the period from January 1, 2003 to December 31, 2013, the ARMAGARCH models were estimated to remove the autoregressive and conditional heteroscedastic effects from the time series of the daily returns. Then, the copula models were used to estimate the dependence relationships between the European stock indexes and the North American stock index, from the precrisis subperiod to the crisis subperiod. The results indicate financial contagion of the subprime crisis for all analyzed European countries. The North European markets intensified the relations of financial integration (both in negative and positive shocks) with the North American market, apart from the Danish against the Portuguese. In addition to the contribution made by the joint application of the ARMA-GARCH models, the findings are useful to identify channels of financial contagion between markets and to warn about the effects of possible new crisis, which will require different levels of adaptation by the companies’ financial managers and intervention by the authorities.
- Asymmetric wealth effect between US stock markets and US housing market and european stock markets: evidences from TAR and MTARPublication . Coelho, Pedro; Gomes, Luís; Ramos, PatríciaEvidence of the asymmetric wealth effect has important implications for investors and continues to merit research attention, not least because much of the evidence based on linear models has been refuted. Indeed, stock and house prices are influenced by economic activity and react nonlinearly to positive/negative shocks. This problem justifies our research. The objective of this study is to examine evidence of cointegrations between the US housing and stock markets and between the US and European stock markets, given the international relevance of these exchanges. Using data from 1989:Q1 to 2020:Q2, the Threshold Autoregression model as well as the Momentum Threshold Autoregression model were calculated by combining the US Freddie, DJIA, and SPX indices and the European STOXX and FTSE indices. The results suggest a long-term equilibrium relationship with asymmetric adjustments between the housing market and the US stock markets, as well as between the DJIA, SPX, and FTSE indices. Moreover, the wealth effect is stronger when stock prices outperform house prices above an estimated threshold. This empirical evidence is useful to portfolio managers in their search for non-perfectly related markets that allow investment diversification and control risk exposure across different assets.
- Memória de longo prazo nos retornos acionistas dos índices de referência da euronext, implicações para a hipótese de mercados eficientes e contributo fractal para aperfeiçoamento do capital asset pricing modelPublication . Gomes, LuísNão existe uma definição única de processo de memória de longo prazo. Esse processo é geralmente definido como uma série que possui um correlograma decaindo lentamente ou um espectro infinito de frequência zero. Também se refere que uma série com tal propriedade é caracterizada pela dependência a longo prazo e por não periódicos ciclos longos, ou que essa característica descreve a estrutura de correlação de uma série de longos desfasamentos ou que é convencionalmente expressa em termos do declínio da lei-potência da função auto-covariância. O interesse crescente da investigação internacional no aprofundamento do tema é justificado pela procura de um melhor entendimento da natureza dinâmica das séries temporais dos preços dos ativos financeiros. Em primeiro lugar, a falta de consistência entre os resultados reclama novos estudos e a utilização de várias metodologias complementares. Em segundo lugar, a confirmação de processos de memória longa tem implicações relevantes ao nível da (1) modelação teórica e econométrica (i.e., dos modelos martingale de preços e das regras técnicas de negociação), (2) dos testes estatísticos aos modelos de equilíbrio e avaliação, (3) das decisões ótimas de consumo / poupança e de portefólio e (4) da medição de eficiência e racionalidade. Em terceiro lugar, ainda permanecem questões científicas empíricas sobre a identificação do modelo geral teórico de mercado mais adequado para modelar a difusão das séries. Em quarto lugar, aos reguladores e gestores de risco importa saber se existem mercados persistentes e, por isso, ineficientes, que, portanto, possam produzir retornos anormais. O objetivo do trabalho de investigação da dissertação é duplo. Por um lado, pretende proporcionar conhecimento adicional para o debate da memória de longo prazo, debruçando-se sobre o comportamento das séries diárias de retornos dos principais índices acionistas da EURONEXT. Por outro lado, pretende contribuir para o aperfeiçoamento do capital asset pricing model CAPM, considerando uma medida de risco alternativa capaz de ultrapassar os constrangimentos da hipótese de mercado eficiente EMH na presença de séries financeiras com processos sem incrementos independentes e identicamente distribuídos (i.i.d.). O estudo empírico indica a possibilidade de utilização alternativa das obrigações do tesouro (OT’s) com maturidade de longo prazo no cálculo dos retornos do mercado, dado que o seu comportamento nos mercados de dívida soberana reflete a confiança dos investidores nas condições financeiras dos Estados e mede a forma como avaliam as respetiva economias com base no desempenho da generalidade dos seus ativos. Embora o modelo de difusão de preços definido pelo movimento Browniano geométrico gBm alegue proporcionar um bom ajustamento das séries temporais financeiras, os seus pressupostos de normalidade, estacionariedade e independência das inovações residuais são adulterados pelos dados empíricos analisados. Por isso, na procura de evidências sobre a propriedade de memória longa nos mercados recorre-se à rescaled-range analysis R/S e à detrended fluctuation analysis DFA, sob abordagem do movimento Browniano fracionário fBm, para estimar o expoente Hurst H em relação às séries de dados completas e para calcular o expoente Hurst “local” H t em janelas móveis. Complementarmente, são realizados testes estatísticos de hipóteses através do rescaled-range tests R/S , do modified rescaled-range test M - R/S e do fractional differencing test GPH. Em termos de uma conclusão única a partir de todos os métodos sobre a natureza da dependência para o mercado acionista em geral, os resultados empíricos são inconclusivos. Isso quer dizer que o grau de memória de longo prazo e, assim, qualquer classificação, depende de cada mercado particular. No entanto, os resultados gerais maioritariamente positivos suportam a presença de memória longa, sob a forma de persistência, nos retornos acionistas da Bélgica, Holanda e Portugal. Isto sugere que estes mercados estão mais sujeitos a maior previsibilidade (“efeito José”), mas também a tendências que podem ser inesperadamente interrompidas por descontinuidades (“efeito Noé”), e, por isso, tendem a ser mais arriscados para negociar. Apesar da evidência de dinâmica fractal ter suporte estatístico fraco, em sintonia com a maior parte dos estudos internacionais, refuta a hipótese de passeio aleatório com incrementos i.i.d., que é a base da EMH na sua forma fraca. Atendendo a isso, propõem-se contributos para aperfeiçoamento do CAPM, através da proposta de uma nova fractal capital market line FCML e de uma nova fractal security market line FSML. A nova proposta sugere que o elemento de risco (para o mercado e para um ativo) seja dado pelo expoente H de Hurst para desfasamentos de longo prazo dos retornos acionistas. O expoente H mede o grau de memória de longo prazo nos índices acionistas, quer quando as séries de retornos seguem um processo i.i.d. não correlacionado, descrito pelo gBm(em que H = 0,5 , confirmando- se a EMH e adequando-se o CAPM), quer quando seguem um processo com dependência estatística, descrito pelo fBm(em que H é diferente de 0,5, rejeitando-se a EMH e desadequando-se o CAPM). A vantagem da FCML e da FSML é que a medida de memória de longo prazo, definida por H, é a referência adequada para traduzir o risco em modelos que possam ser aplicados a séries de dados que sigam processos i.i.d. e processos com dependência não linear. Então, estas formulações contemplam a EMH como um caso particular possível.
- Persistence characteristics in financial prices: evidence from the portuguese stock market returnsPublication . Gomes, LuísThe objective of this article is to provide additional knowledge to the discussion of long-term memory, leaning over the behavior of the main Portuguese stock index. The first four moments are calculated using time windows of increasing size and sliding time windows of fixed size equal to 50 days and suggest that daily returns are non-ergodic and non-stationary. Seeming that the series is best described by a fractional Brownian motion approach, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA). The findings indicate evidence of long term memory in the form of persistence. This evidence of fractal structure suggests that the market is subject to greater predictability and contradicts the efficient market hypothesis in its weak form. This raises issues regarding theoretical modeling of asset pricing. In addition, we carried out a more localized (in time) study to identify the evolution of the degree of long-term dependency over time using windows 200-days and 400-days. The results show a switching feature in the index, from persistent to anti-persistent, quite evident from 2010.
- Sustainability balanced scorecard for a brazilian agricultural and livestock companyPublication . Araújo, Lindiana; Costa Oliveira, Helena; Gomes, LuísThe agricultural sector in Brazil has a noticeable impact on its wealth and a significant effect on sustainability. This study presents the corporate sustainability management through the integration of social and environmental issues in the traditional Balanced Scorecard, that is, through a Sustainability Balanced Scorecard (SBSC). It establishes causal relationships between economic, social and environmental perspectives, and highlights its potential impacts. This study relays on the Brazilian company with the largest amount of agricultural land. This company acquires, develop, exploit and commercialize rural properties that are suitable for agriculture. The main purpose of this paper is to study the company and to propose an SBSC. We present a qualitative case study based on interviews and on documental analysis. We conclude that, through this framework, sustainability can be aligned with the strategic management of the company. The implementation of an SBSC provides organizational benefits and must take into consideration the peculiarities of each organization.