The Dynamics of Inflation and Currency Substitution in a Small Open Economy

In this paper, we analyse the relationship between money and inflation in a small open economy where domestic and foreign currencies are perfect substitutes as means of payment. It is shown that, if the path of domestic money supply is such that individuals find it optimal to change the currency in which transactions are settled, there will be an adjustment period during which domestic inflation adjusts so as to equalise the foreign inflation rate. In the case of a disinflation program, it is shown that the foreign currency is not necessarily abandoned as means of payment. The results obtained are consistent with both dollarisation hysteresis and reversibility, without requiring the specification of dollarisation costs.currency substitution, dollarisation, money-demand and hysteresis.

Currency Substitution, Portfolio Diversification and Money Demand

The paper explores the implications of means of payment substitutability and capital mobility on the properties of the money demand, using the Thomas (1985) stochastic dynamic optimising model, where the specific role of money is explicitly accounted for. Extending the model to a case in which the consumer has no access to bonds denominated in foreign currency, we are able to describe the double role (means of payment and store of value) that foreign bank notes may have in countries where asset markets are illiquid. We show that means of payment substitutability opens a channel through which portfolio decisions influence the demand for domestic money, even if the later is dominated as store of value. Contrary to what suggested by the Portfolio Balance Theory of Currency Substitution (Cuddington, 1983), the results obtained in this paper suggest that the significance of an expected exchange rate depreciation term in the demand for domestic money provides a valid test for the presence of CSMoney Demand, Currency Substitution, Dollarisation, Portfolio Choice.

A Cloud-ready Architecture for Shared Medical Imaging Repository

Background and Objective: Nowadays usage paradigms of medical imaging resources are requesting vendor-neutral archives, accessible through standard interfaces, with multi-repository support. Regional repositories shared by distinct institutions, teleradiology as a service at Cloud, teaching and research archives, are illustrative examples of this new reality. However, traditional production environments have a server archive instance per functional domain where every registered client application has access to all studies. This paper proposes an innovator ownership concept and access control mechanisms that provide a multi-repository environment and integrates well with standard protocols. Methods: A secure accounting mechanism for medical imaging repositories were designed and instantiated as an extension of a well-known open-source archive. A new Web services layer was implemented to provide a vendor-neutral solution complaint with modern DICOM-Web protocols for storage, search and retrieve of medical imaging data. Results: The concept validation was done through the integration of proposed architecture in an open-source solution. A quantitative assessment was performed for evaluating the impact of the mechanism in the usual DICOM Web operations. Conclusions: This article proposes a secure accounting architecture able to easily convert a standard medical imaging archive server in a multi-repository solution. The proposal validation was done through a set of tests that demonstrated its robustness and usage feasibility in a production environment. The proposed system offers new services, fundamental in a new era of Cloud-based operations, with acceptable temporal costs.Comment: 9 pages, 7 figures and 2 tables. Journal submissio

Currency substitution and money demand in Euroland

This papers tests the stability of the demand for money in the euro area in the context of an open economy. A sample consisting of quarterly data covering the 1982:2-1999:3 period is considered. The main finding is that the US long term rate of interest plays a significant role in the European money demand relationship. This result holds for different combinations of variables forming the vector auto-regressive system and suggests that currency substitution vis-à-vis the US dollar may be an important factor influencing the ECB monetary policy.EMU, Money Demand, International Currencies, Currency Substitution.

Dynamic Bayesian networks in molecular plant science: inferring gene regulatory networks from multiple gene expression time series

To understand the processes of growth and biomass production in plants, we ultimately need to elucidate the structure of the underlying regulatory networks at the molecular level. The advent of high-throughput postgenomic technologies has spurred substantial interest in reverse engineering these networks from data, and several techniques from machine learning and multivariate statistics have recently been proposed. The present article discusses the problem of inferring gene regulatory networks from gene expression time series, and we focus our exposition on the methodology of Bayesian networks. We describe dynamic Bayesian networks and explain their advantages over other statistical methods. We introduce a novel information sharing scheme, which allows us to infer gene regulatory networks from multiple sources of gene expression data more accurately. We illustrate and test this method on a set of synthetic data, using three different measures to quantify the network reconstruction accuracy. The main application of our method is related to the problem of circadian regulation in plants, where we aim to reconstruct the regulatory networks of nine circadian genes in Arabidopsis thaliana from four gene expression time series obtained under different experimental conditions

Heterogeneous continuous dynamic Bayesian networks with flexible structure and inter-time segment information sharing

Classical dynamic Bayesian networks (DBNs) are based on the homogeneous Markov assumption and cannot deal with heterogeneity and non-stationarity in temporal processes. Various approaches to relax the homogeneity assumption have recently been proposed. The present paper aims to improve the shortcomings of three recent versions of heterogeneous DBNs along the following lines: (i) avoiding the need for data discretization, (ii) increasing the flexibility over a time-invariant network structure, (iii) avoiding over-flexibility and overfitting by introducing a regularization scheme based in inter-time segment information sharing. The improved method is evaluated on synthetic data and compared with alternative published methods on gene expression time series from Drosophila melanogaster. 1

The dynamics of inflation and currency substitution in a small open economy

In this paper, we analyse the relationship between money and inflation in a small open economy where domestic and foreign currencies are perfect substitutes as means of payment. It is shown that, if the path of domestic money supply is such that individuals find it optimal to change the currency in which transactions are settled, there will be an adjustment period during which domestic inflation adjusts so as to equalise the foreign inflation rate. In the case of a disinflation program, it is shown that the foreign currency is not necessarily abandoned as means of payment. The results obtained are consistent with both dollarisation hysteresis and reversibility, without requiring the specification of dollarisation costs.currency substitution, dollarisation, money-demand and hysteresis

Portugal-EU convergence revisited: evidence for the period 1960-2003

This paper uses the stochastic approach to convergence to investigate whether real per capita GDP in Portugal has been converging to the EU15 average. The estimation accounts for conditional convergence, transitional dynamics and up to two structural breaks. It is found that per capita GDP in Portugal has indeed converged to the EU15 average, but the pace convergence has not been uniform along time. In particular, a slow down in the convergence process is identified in 1974. This result depends, however, as to whether the choice of this break-date is viewed as uncorrelated with the data. No evidence of acceleration in the speed of convergence is found after EC accession, in 1986.Unit root test, Income convergence, The Portuguese Economy.