Openness and optimal monetary policy

We show that the composition of imports has important implications for the optimal volatility of the exchange rate. Using input-output data for 25 countries we document substantial differences in the import and non-tradable content of final demand components, and in the role played by imported inputs in domestic production. We build a business cycle model of a small open economy to discuss how the problem of the optimizing policy-maker changes endogenously as the composition of imports and of final demand is altered. Contrary to models where steady state trade openness is entirely characterized by home bias, we find that trade openness is a very poor proxy of the welfare impact of alternative monetary policies. Finally, we quantify the loss from an exchange rate peg relative to the Ramsey policy conditional on the composition of imports, using parameter values that are estimated from OECD input-output tables data. We find that the main determinant of the losses is the share of non-traded goods in final demand. JEL Classification: E52, E31, F02, F41Exchange Rate Regimes, international trade, Non-tradable Goods, Optimal Policy

Untenable nonstationarity: An assessment of the fitness for purpose of trend tests in hydrology

The detection and attribution of long-term patterns in hydrological time series have been important research topics for decades. A significant portion of the literature regards such patterns as ‘deterministic components’ or ‘trends’ even though the complexity of hydrological systems does not allow easy deterministic explanations and attributions. Consequently, trend estimation techniques have been developed to make and justify statements about tendencies in the historical data, which are often used to predict future events. Testing trend hypothesis on observed time series is widespread in the hydro-meteorological literature mainly due to the interest in detecting consequences of human activities on the hydrological cycle. This analysis usually relies on the application of some null hypothesis significance tests (NHSTs) for slowly-varying and/or abrupt changes, such as Mann-Kendall, Pettitt, or similar, to summary statistics of hydrological time series (e.g., annual averages, maxima, minima, etc.). However, the reliability of this application has seldom been explored in detail. This paper discusses misuse, misinterpretation, and logical flaws of NHST for trends in the analysis of hydrological data from three different points of view: historic-logical, semantic-epistemological, and practical. Based on a review of NHST rationale, and basic statistical definitions of stationarity, nonstationarity, and ergodicity, we show that even if the empirical estimation of trends in hydrological time series is always feasible from a numerical point of view, it is uninformative and does not allow the inference of nonstationarity without assuming a priori additional information on the underlying stochastic process, according to deductive reasoning. This prevents the use of trend NHST outcomes to support nonstationary frequency analysis and modeling. We also show that the correlation structures characterizing hydrological time series might easily be underestimated, further compromising the attempt to draw conclusions about trends spanning the period of records. Moreover, even though adjusting procedures accounting for correlation have been developed, some of them are insufficient or are applied only to some tests, while some others are theoretically flawed but still widely applied. In particular, using 250 unimpacted stream flow time series across the conterminous United States (CONUS), we show that the test results can dramatically change if the sequences of annual values are reproduced starting from daily stream flow records, whose larger sizes enable a more reliable assessment of the correlation structures

Photon localization versus population trapping in a coupled-cavity array

We consider a coupled-cavity array (CCA), where one cavity interacts with a two-level atom under the rotating-wave approximation. We investigate the excitation transport dynamics across the array, which arises in the atom's emission process into the CCA vacuum. Due to the known formation of atom-photon bound states, partial field localization and atomic population trapping in general take place. We study the functional dependance on the coupling strength of these two phenomena and show that the threshold values beyond which they become significant are different. As the coupling strength grows from zero, field localization is exhibited first.Comment: 9 pages, 5 figures. Replaced one plot in Fig.

Market soundings: the interaction between securities regulation and company law in the United Kingdom and Italy

Before deciding on operations involving share issuance or sale, companies or shareholders may seek to disclose information to selected investors, in order to gauge their opinion on the envisaged market operation. Despite such “market soundings” risk violating the prohibition of insider trading, selective disclosures have been partially accepted in several European jurisdictions. Market soundings have been eventually regulated in the MAR, which clarifies under which circumstances they are allowed and the position of the involved parties. This article analyses the rules on market soundings in the MAR with regard to issuance in the secondary market and accelerated bookbuildings. In this context, the question arises of whether harmonised rules on market soundings are compatible with national company law regimes. To address this issue, it will be assessed how Italian and English company law regimes react towards selective disclosures. It will be shown that a tension may still exist between uniform rules on market abuses and national company law rules, mostly with regard to directors’ duties and liabilities

Rainfall thresholds and flood warning: an operative case study

Abstract. An operative methodology for rainfall thresholds definition is illustrated, in order to provide at critical river section optimal flood warnings. Threshold overcoming could produce a critical situation in river sites exposed to alluvial risk and trigger the prevention and emergency system alert. The procedure for the definition of critical rainfall threshold values is based both on the quantitative precipitation observed and the hydrological response of the basin. Thresholds values specify the precipitation amount for a given duration that generates a critical discharge in a given cross section and are estimated by hydrological modelling for several scenarios (e.g.: modifying the soil moisture conditions). Some preliminary results, in terms of reliability analysis (presence of false alarms and missed alarms, evaluated using indicators like hit rate and false alarm rate) for the case study of Mignone River are presented

Rainfall stochastic modeling for runoff forecasting

Rainfall fields estimation over a catchment area is an important stage in many hydrological application. In this context weather radars have several advantages since a single site is able to obtain coverage over a vast area with very high temporal and spatial resolution and the advent of weather radar systems with dual polarization capability allowed progress on radar rainfall estimation and its hydro-meteorological applications. For these applications of radar data it was necessary to remove the ground clutter contamination with an algorithm based on the backscattering signal variance of the differential reflectivity. The calibration of the GDSTM model (Gaussian Displacements Spatial-Temporal Model), a cluster stochastic generation model in continuous space and time, is presented. In this model storms arrive in a Poisson process in time with cells occurring in each storm that cluster in space and time. The model is calibrated, using data collected by the weather radar Polar 55C located in Rome, inside a square area of 132x132 km2, with the radar at the center. The GDSTM is fitted to sequences of radar images with a time interval between the PPIs scans of 5 minutes. A generalized method of moments procedure is used for parameters estimation. For the validation of the ability of the model to reproduce the internal structure of rain event a geomorphological rainfall-runoff model based on width function (WFIUH) was calibrated using data simulated and observed data. Several rainfall fields are generated with the stochastic model and then they are used as input of the WFIUH model so that the forecasted discharges can be compared to the observed ones

Desarrollo de una herramienta para la gestión de los pastoreos en praderas y verdeos con vacunos en crecimiento y terminación

El objetivo principal de este trabajo es desarrollar una herramienta (“enPastoreo”) de soporte a la gestión de los pastoreos, para ganado de carne en crecimiento y engorde sobre pasturas sembradas para Uruguay, verificando su funcionalidad a nivel comercial y relevando el grado de satisfacción a nivel de usuarios. La herramienta está disponible en versión web y también se puede descargar la aplicación desde el store del dispositivo móvil. En el caso de la APP web, está desarrollada bajo la filosofía de diseño Responsive Web Design que permite su correcta visualización desde cualquier dispositivo.Sociedad Argentina de Informática e Investigación Operativ

Desarrollo de una herramienta para la gestión de los pastoreos en praderas y verdeos con vacunos en crecimiento y terminación

El objetivo principal de este trabajo es desarrollar una herramienta (“enPastoreo”) de soporte a la gestión de los pastoreos, para ganado de carne en crecimiento y engorde sobre pasturas sembradas para Uruguay, verificando su funcionalidad a nivel comercial y relevando el grado de satisfacción a nivel de usuarios. La herramienta está disponible en versión web y también se puede descargar la aplicación desde el store del dispositivo móvil. En el caso de la APP web, está desarrollada bajo la filosofía de diseño Responsive Web Design que permite su correcta visualización desde cualquier dispositivo.Sociedad Argentina de Informática e Investigación Operativ