Endogenous Cycles in Optimal Monetary Policy with a Nonlinear Phillips Curve

There is by now a large consensus in modern monetary policy. This consensus has been built upon a dynamic general equilibrium model of optimal monetary policy with sticky prices a la Calvo and forward looking behavior. In this paper we extend this standard model by introducing nonlinearity into the Phillips curve. As the linear Phillips curve may be questioned on theoretical grounds and seems not to be favoured by empirical evidence, a similar procedure has already been undertaken in a series papers over the last few years, e.g., Schaling (1999), Semmler and Zhang (2004), Nobay and Peel (2000), Tambakis (1999), and Dolado et al. (2004). However, these papers were mainly concerned with the analysis of the problem of inflation bias, by deriving an interest rate rule which is nonlinear, leaving the issues of stability and the possible existence of endogenous cycles in such a framework mostly overlooked. Under the specific form of nonlinearity proposed in our paper (which allows for both convexity and concavity and secures closed form solutions), we show that the introduction of a nonlinear Phillips curve into a fully deterministic structure of the standard model produces significant changes to the major conclusions regarding stability and the efficiency of monetary policy in the standard model. We should emphasize the following main results: (i) instead of a unique fixed point we end up with multiple equilibria; (ii) instead of saddle--path stability, for different sets of parameter values we may have saddle stability, totally unstable and chaotic fixed points (endogenous cycles); (iii) for certain degrees of convexity and/or concavity of the Phillips curve, where endogenous fluctuations arise, one is able to encounter various results that seem interesting. Firstly, when the Central Bank pays attention essentially to inflation targeting, the inflation rate may have a lower mean and is certainly less volatile; secondly, for changes in the degree of price stickiness the results are not are clear cut as in the previous case, however, we can also observe that when such stickiness is high the inflation rate tends to display a somewhat larger mean and also higher volatility; and thirdly, it shows that the target values for inflation and the output gap (π^,x^), both crucially affect the dynamics of the economy in terms of average values and volatility of the endogenous variables --- e.g., the higher the target value of the output gap chosen by the Central Bank, the higher is the inflation rate and its volatility --- while in the linear case only the π^ does so (obviously, only affecting in this case the level of the endogenous variables). Moreover, the existence of endogenous cycles due to chaotic motion may raise serious questions about whether the old dictum of monetary policy (that the Central Bank should conduct policy with discretion instead of commitment) is not still very much in the business of monetary policy.Optimal monetary policy, Interest Rate Rules, Nonlinear Phillips Curve, Endogenous Fluctuations and Stabilization

Chaotic Dynamics in Optimal Monetary Policy

There is by now a large consensus in modern monetary policy. This consensus has been built upon a dynamic general equilibrium model of optimal monetary policy as developed by, e.g., Goodfriend and King (1997), Clarida et al. (1999), Svensson (1999) and Woodford (2003). In this paper we extend the standard optimal monetary policy model by introducing nonlinearity into the Phillips curve. Under the specific form of nonlinearity proposed in our paper (which allows for convexity and concavity and secures closed form solutions), we show that the introduction of a nonlinear Phillips curve into the structure of the standard model in a discrete time and deterministic framework produces radical changes to the major conclusions regarding stability and the efficiency of monetary policy. We emphasize the following main results: (i) instead of a unique fixed point we end up with multiple equilibria; (ii) instead of saddle--path stability, for different sets of parameter values we may have saddle stability, totally unstable equilibria and chaotic attractors; (iii) for certain degrees of convexity and/or concavity of the Phillips curve, where endogenous fluctuations arise, one is able to encounter various results that seem intuitively correct. Firstly, when the Central Bank pays attention essentially to inflation targeting, the inflation rate has a lower mean and is less volatile; secondly, when the degree of price stickiness is high, the inflation rate displays a larger mean and higher volatility (but this is sensitive to the values given to the parameters of the model); and thirdly, the higher the target value of the output gap chosen by the Central Bank, the higher is the inflation rate and its volatility.Comment: 11 page

Revisão dos desenhos de pesquisa relevantes para enfermagem: Parte 1: desenhos de pesquisa quantitativa

This three part series of articles provides a brief overview of relevant research designs in nursing. The first article in the series presents the most frequently used quantitative research designs. Strategies for non-experimental and experimental research designs used to generate and refine nursing knowledge are described. In addition, the importance of quantitative designs and the role they play in developing evidence-based practice are discussed. Nursing care needs to be determined by the results of sound research rather than by clinical preferences or tradition.Esta serie de tres artículos muestra una breve revisión de los diseños de investigación resaltantes para Enfermería. En el primer artículo de la serie son revisados los diseños de investigación cuantitativa mas utilizados en la actualidad para las investigaciones en esta área del conocimiento. Son indicados los tipos de estrategias que tales diseños utilizan para generar y refinar conocimiento siendo descritos los diseños clasificados como no experimentales y experimentales. A modo de conclusión se resalta sobre la importancia de la práctica basada en evidencia para la profesión, de forma que el cuidado de enfermería sea determinado por resultados de investigación sólida y no de acuerdo con preferencias clínicas o tradicionales.Esta série de três artigos apresenta uma breve revisão dos desenhos de pesquisa relevantes para a enfermagem. Neste primeiro artigo da série são revistos os desenhos de pesquisa quantitativa mais utilizados atualmente nas investigações desta área de conhecimento. São apontados os tipos de estratégia que tais desenhos utilizam para gerar e refinar conhecimento e são descritos os desenhos classificados como não-experimentais e experimentais. A guisa de conclusão ressalta-se a importância da prática baseada em evidência para a profissão, de modo que o cuidado de enfermagem seja determinado por resultados de pesquisa sólida e não por preferências clínicas ou por tradição

Revisão dos desenhos de pesquisa relevantes para enfermagem: Parte 3: Métodos mistos e múltiplos

This third article of the series "An Overview of Research Designs Relevant to Nursing" presents the use of mixed or multiple methods in nursing research. The use of mixed or multiple methods is a growing trend that offers another option for researchers in addressing the complex health problems faced in nursing today. Understanding of all methods and all combinations of methods facilitate the conduction and dissemination of research to serve nursing practice.Este tercero artículo de la serie "Revisión de los Diseños de Investigación Relevantes para la Enfermería" presenta el uso de los métodos mixtos o múltiples en la investigación en enfermería. El uso de métodos mixtos o múltiples es una tendencia creciente que ofrece una alternativa a los investigadores en la aproximación de problemas complejos de la salud enfrentados actualmente en la enfermería. Entender todos los métodos y todas las combinaciones de métodos facilita la conducción y diseminación de la investigación para servir a la práctica de la enfermería.Este terceiro artigo da série "Revisão dos Desenhos de Pesquisa Relevantes para Enfermagem" apresenta o uso dos métodos mistos ou múltiplos na pesquisa em enfermagem. O uso de métodos mistos ou múltiplos é uma tendência crescente que oferece uma alternativa aos pesquisadores na abordagem de problemas complexos da saúde enfrentados atualmente em enfermagem. Entender todos os métodos e todas as combinações de métodos facilita a condução e disseminação da pesquisa para servir a prática da enfermagem

An overview of research designs relevant to nursing: part 2: qualitative research designs

This second article of the series An Overview of Research Designs Relevant to Nursing presents qualitative research designs. Phenomenological, ground theory, ethnography, narrative inquiry, and other related qualitative-related research methodologies are described. In addition, the importance of qualitative research as groundwork for quantitative studies is discussed. This link between qualitative and quantitative research is fundamental to promote evidence-based nursing practice.Este segundo artigo da série Revisão dos Desenhos de Pesquisa Relevantes para Enfermagem apresenta desenhos de pesquisa qualitativa. São descritas metodologias fenomenológicas, teoria fundamentada nos dados, etnografia, investigação narrativa, entre outras. É também discutida a importância da pesquisa qualitativa como base para estudos quantitativos. Essa conexão entre pesquisa qualitativa e quantitativa é fundamental para promover a prática de enfermagem baseada em evidência.Este segundo artículo de la serie de Revisión de los Diseños de Investigación Relevantes para Enfermería presenta los diseños de investigación cualitativa. Son descritas metodologías fenomenológicas, teoría fundamentada en los datos, etnografía, investigación narrativa entre las principales. Así mismo se discute la importancia de la investigación cualitativa como base para estudios cuantitativos. Esta conexión entre investigación cualitativa y cuantitativa es fundamental para promover la práctica de enfermería basada en evidencias

Developing a methodology for XPS profiling of biofilms and biological materials

Films of cells on solid substrates are encountered in a variety of biological and biomedical environments, including cells in biofilms that spontaneously colonize medical devices and multilayers of cells filtered from suspensions for analysis. Understanding the chemical properties of cells in such films is important for providing clues about the behavior of the cells or about the effects of treatments that had been applied to the cells. X-ray Photoelectron Spectroscopy (XPS), with its combination of chemical selectivity and surface specificity, is an ideal technique for analysing these biofilms and multilayers, but it needs to be combined with profiling to more fully characterise the samples. It is well known that profiling with traditionally used argon monomers results in a high degree of chemical modification for most organic materials. Recent studies have shown, however, that argon cluster beams may be used for depth profiling of organic materials while preserving the chemical information. This poster will present data from cluster profiling studies of biofilms and biomaterials. The methodology required for optimum profiling of these samples will be discussed, including an evaluation of XPS data acquisition protocols, as well as sputtering conditions

Fistulização para o Cólon de Sonda Jejunal de PEG-J num Doente Tratado com Infusão de Duodopa®: Caso Clínico

The continuous delivery of a levodopa/carbidopa gel suspension (Duodopa®) into the small bowel through a jejunal tube inserted via percutaneous endoscopic gastrostomy represents a new treatment method in advanced Parkinson disease. Some severe device-related complications have been described in the last few years. Some of them are associated with phytobezoar formation at the pigtail of the catheter. We present the case of a Parkinson disease patient treated with the Duodopa infusion system complicated by jejunal tube fistulization into the colon. We suggest a possible treatment strategy for this complication, which has not been described in the literature to date.info:eu-repo/semantics/publishedVersio

Evaluation of Xgboost and Lgbm Performance in Tree Species Classification with Sentinel-2 Data

Los, H., Mendes, G. S., Cordeiro, D., Grosso, N., Costa, H., Benevides, P., & Caetano, M. (2021). Evaluation of Xgboost and Lgbm Performance in Tree Species Classification with Sentinel-2 Data. In IGARSS 2021 - 2021 IEEE International Geoscience and Remote Sensing Symposium: Proceedings (pp. 5803-5806). IEEE. https://doi.org/10.1109/IGARSS47720.2021.9553031Tree species classification with satellite data has become more and more popular since Sentinel-2 launch. We compared efficacy and effectiveness of Extreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LGBM) with widely used in remote sensing Random Forest (RF), Support Vector Machine (SVM) and K-Nearest Neighbour (KNN) algorithms. Analyses were performed over an area in Portugal with multi-temporal Sentinel-2 data registered in April, June, August and October 2018. The selected classes were: cork oak, holm oak, eucalyptus, other broadleaved, maritime pine, stone pine and other coniferous. Algorithm efficacy was measured through F1-score and accuracy while efficiency was measured through the median time needed for each fit. XGBoost and LGBM outperformed efficacy of other algorithms, which was already high (above 90% for the best variant of each algorithm). In terms of efficacy, LGBM overcame all algorithms, including XGBoost.authorsversionpublishe

The workaholism as an obstacle to safety and well-being in the workplace

The work aholism, defined as addiction at work, increase burnout and negatively affects the psychological well-being. It was developed a quantitative study using self-reported measures. This study aims to evaluate the variables: passion for work, work engagement, engagement for life and job satisfaction as predictors of workaholism and the effects of workaholism on the psychological well-being and burnout. With a sample of 199 workers, the results of multiple linear regression analysis allowed to identify that some of the variables and their dimensions have significant effects on the workaholism and on psychological well-being and burnout