Is the US Fiscal Deficit Sustainable? A Fractionally Integrated and Cointegrated Approach

The sustainability of fiscal deficits has received in recent years increasing attention from economists. Empirical work has concentrated on both the univariate properties of debt and the cointegration properties of public revenues and expenditures. In this paper, we examine if sustainability of the US fiscal deficit holds by means of studying the univariate properties of the difference between public revenues and expenditures. However, instead of using classical approaches based on I(1) or I(0) integration techniques, we use a methodology based on fractional processes. The results show that the public deficit in the US is an I(d) process with d slightly smaller than 1, implying that fiscal deficit is mean reverting, and thus, sustainable, though the adjustment process towards equilibrium will take a very long time.

Additional Empirical Evidence on Real Convergence: A Fractionally Integrated Approach

This article examines the real convergence hypothesis in 15 OECD countries. For this purpose, we examine the order of integration of the real GDP per capita series in these countries as well as their differences with respect to the US which is used as a benchmark country. We use both parametric and semiparametric methods and the results show that convergence is only achieved in half of the countries, namely, Austria, Australia, Canada, Finland, Germany, Japan and the UK. On the contrary, the results for Belgium, Denmark, France, Italy, the Netherlands, Norway and Sweden show strong evidence against this hypothesis.

Time Series

This paper first shows that survey-based expectations (SBE) outperform standard time series models in U.S. quarterly inflation out-of-sample prediction and that the term structure of survey-based inflation forecasts has predictive power over the path of future inflation changes. It then proposes some empirical explanations for the forecasting success of survey-based inflation expectations. We show that SBE pool a large amount of heterogeneous information on inflation expectations and react more flexibly and accurately to macro conditions both contemporaneously and dynamically. We illustrate the flexibility of SBE forecasts in the context of the recent financial crisis

Exploring the Concept of the Digital Educator During COVID-19

T In many machine learning classification problems, datasets are usually of high dimensionality and therefore require efficient and effective methods for identifying the relative importance of their attributes, eliminating the redundant and irrelevant ones. Due to the huge size of the search space of the possible solutions, the attribute subset evaluation feature selection methods are not very suitable, so in these scenarios feature ranking methods are used. Most of the feature ranking methods described in the literature are univariate methods, which do not detect interactions between factors. In this paper, we propose two new multivariate feature ranking methods based on pairwise correlation and pairwise consistency, which have been applied for cancer gene expression and genotype-tissue expression classification tasks using public datasets. We statistically proved that the proposed methods outperform the state-of-the-art feature ranking methods Clustering Variation, Chi Squared, Correlation, Information Gain, ReliefF and Significance, as well as other feature selection methods for attribute subset evaluation based on correlation and consistency with the multi-objective evolutionary search strategy, and with the embedded feature selection methods C4.5 and LASSO. The proposed methods have been implemented on the WEKA platform for public use, making all the results reported in this paper repeatable and replicabl

Compromised Photosynthetic Electron Flow and H2O2 Generation Correlate with Genotype-Specific Stomatal Dysfunctions during Resistance against Powdery Mildew in Oats

Stomatal dysfunction known as "locking" has been linked to the elicitation of a hypersensitive response (HR) following attack of fungal pathogens in cereals. We here assess how spatial and temporal patterns of different resistance mechanisms, such as HR and penetration resistance influence stomatal and photosynthetic parameters in oat (Avena sativa) and the possible involvement of hydrogen peroxide (H2O2) in the dysfunctions observed. Four oat cultivars with differential resistance responses (i.e., penetration resistance, early and late HR) to powdery mildew (Blumeria graminis f. sp. avenae, Bga) were used. Results demonstrated that stomatal dysfunctions were genotype but not response-type dependent since genotypes with similar resistance responses when assessed histologically showed very different locking patterns. Maximum quantum yield (Fv/Fm) of photosystem II were compromised in most Bga-oat interactions and photoinhibition increased. However, the extent of the photosynthetic alterations was not directly related to the extent of HR. H2O2 generation is triggered during the execution of resistance responses and can influence stomatal function. Artificially increasing H2O2 by exposing plants to increased light intensity further reduced Fv/Fm ratios and augmented the patterns of stomatal dysfunctions previously observed. The latter results suggest that the observed dysfunctions and hence a cost of resistance may be linked with oxidative stress occurring during defense induced photosynthetic disruption

Conversion of aqueous ethanol/acetaldehyde mixtures into 1,3-butadiene over a mesostructured Ta-SBA-15 catalyst: Effect of reaction conditions and kinetic modelling

This paper studies key issues for the design of industrial ethanol to 1,3-butadiene two-step processes, focusing on the second catalytic reaction step, for which a Ta-SBA-15 catalyst was chosen as a representative of the new generation of two-step catalysts. The important practical aspects studied were: i) the effect of operating conditions and the presence of impurities (water) in the ethanol feedstock on the performance of the catalyst, ii) stability and regeneration of the catalyst, and iii) the development of a kinetic model that can be used as a tool for designing the industrial process. The results showed that there are large non-linear interacting effects between the reaction conditions (temperature, space velocity and ethanol/acetaldehyde mole ratio) which must be carefully selected to optimize the catalyst performance. When shifting from an anhydrous to an aqueous ethanol/acetaldehyde feed (7.5 wt% water), catalyst performance at high temperature barely changed while at low temperature, conversion of ethanol and acetaldehyde decreased. Water in the feed largely increased the stability of Ta-SBA-15 catalyst. Finally, a kinetic model of a fresh catalyst was developed, whose novelty lies in the use of kinetic equations that account for the effect of water in the feed on the catalyst performance.Ministerio de Economía, Industria y Competitividad CTQ2015-71427-

Design of splints based on the NiTi alloy for the correction of joint deformities in the fingers

<p>Abstract</p> <p>Background</p> <p>The proximal interphalange joint (PIP) is fundamental for the functional nature of the hand. The contracture in flexion of the PIP, secondary to traumatisms or illnesses leads to an important functional loss. The use of correcting splints is the common procedure for treating this problem. Its functioning is based on the application of a small load and a prolonged stress which can be dynamic, static progressive or static serial.</p> <p>It is important that the therapist has a splint available which can release a constant and sufficient force to correct the contracture in flexion. Nowadays NiTi is commonly used in bio-engineering, due to its superelastical characteristics. The experience of the authors in the design of other devices based on the NiTi alloy, makes it possible to carry out a new design in this work - the production of a finger splint for the treatment of the contracture in flexion of the PIP joint.</p> <p>Methods</p> <p>Commercial orthosis have been characterized using a universal INSTRON 5565 machine. A computational simulation of the proposed design has been conducted, reproducing its performance and using a model "ad hoc" for the NiTi material. Once the parameters have been adjusted, the design is validated using the same type of test as those carried out on commercial orthosis.</p> <p>Results and Discussion</p> <p>For commercial splint the recovering force falls to excessively low values as the angle increases. Angle curves for different lengths and thicknesses of the proposed design have been obtained, with a practically constant recovering force value over a wide range of angles that vary between 30° and 150° in every case. Then the whole treatment is possible with only one splint, and without the need of progressive replacements as the joint recovers.</p> <p>Conclusions</p> <p>A new model of splint based on NiTi alloy has been designed, simulated and tested comparing its behaviour with two of the most regularly used splints. Its uses is recommended instead of other dynamic orthosis used in orthopaedics for the PIP joint. Besides, its extremely simple design, makes its manufacture and use on the part of the specialist easier.</p

Fertilización nitrogenada en olivo cv. Empeltre. II.- composición polifenólica de hojas y frutos y calidad del aceite

4 Pags.- 1 Tabl.- 3 Figs.El establecimiento de posibles relaciones entre el estado nutricional del olivo, la composición polifenólica de sus hojas y frutos y la calidad del aceite, sólo puede llevarse a cabo en experimentos de fertilización controlados, donde se estudie el efecto de un sólo elemento nutriente, manteniendo constantes todos los demás parámetros agronómicos. Este es el objetivo del presente trabajo. Realizar un estudio de este tipo, es tarea compleja, interdisciplinar, y exige un largo periodo de tiempo de observación y seguimiento. Nuestro equipo la ha abordado, aunque consciente de que no se puede llegar en corto plazo a resultados concluyentes. La reconocida calidad de los aceites de Aragón (GRACIA, 1991, 1996, 2001) y la peculiaridad de las principales variedades aquí implantadas, Empeltre y Arbequina, han motivado la puesta en marcha de dos experimentos de fertilización con árboles jóvenes (uno en cada variedad), que puedan contribuir a mejorar su conocimiento. En dos trabajos previos (MONGE et al., 2002 a y b) se da cuenta de los datos relativos a cada uno de los experimentos, así como de los primeros resultados del estudio de los suelos, del estado nutritivo de los árboles y del crecimiento de éstos. El presente trabajo sintetiza los primeros datos obtenidos en el ensayo de fertilización nitrogenada con la variedad Empeltre sobre el contenido de los polifenoles en hoja y fruto y sobre la calidad del aceite.Este trabajo ha sido subvencionado por el MAPA, Programa de Mejora de la Calidad de la Producción de Aceite de Oliva, proyecto CAO99-020-C2.Peer reviewe

Persistence, mean reversion and non-linearities in the US housing prices over 1830-2013

The objective of this study is to provide a direct estimate of the degree of persistence of measures of nominal and real house prices for the US economy, covering the longest possible annual sample of data, namely 1830–2013. The estimation of the degree of persistence accommodates for non-linear (deterministic) trends using Chebyshev polynomials in time. In general, the results show a high degree of persistence in the series along with a component of non-linear behaviour. In general, if we assume uncorrelated errors, non-linearities are observed in both nominal and real prices, but this hypothesis is rejected in favour of linear models for the logtransformation of the data. However, if autocorrelated errors are permitted, non-linearities are observed in all cases, and mean reversion is found in the case of logged prices, though given the wide confidence intervals, the unit root null hypothesis cannot be rejected in these cases.Luis A. Gil-Alana gratefully acknowledges the financial support from the Ministerio de Economía y Competitividad [ECO2014-55236]. Fernando Perez de Gracia also acknowledges the financial support from the Ministerio de Economía y Competitividad [ECO2014-55496].http://www.tandfonline.com/loi/raec202018-01-31hb2016Economic