Inflation targeting in Brazil: what difference does a year make?

The adoption of inflation targeting as a monetary policy strategy in Brazil was a convenient way to replace exchange rate rule by targeted inflation in an effort to anchor inflation expectations. This paper briefly evaluates the inflation target experience from three viewpoints: reasons behind the success, difficulties regarding forecasting and the risks ahead. It analyses the factors behind the success as well as the way initial doubts and a second round of mistrust were successfully dealt with. It looks at the empirical difficulties to estimate a reliable Demand Function and examines evidence on the persistence of high interest rates as captured by a Taylor rule. It points out to possible signaling problems in the transmission mechanism that might lead to a weakening of the confidence in the strategy in the future. Section 3 draws conclusions on risks that emerged together with favorable outcomes of the first year. There has been a substantial progress in the overall confidence in monetary policy's management. Inflation targeting has certainly played a relevant role in this gain. However, it looks like we have not got rid of the "thin ice economy" riding in the post-Real era, since dependence of inflation on foreign exchange availability is still high. Thus the Brazilian economy is still excessively dependent on international liquidity fluctuations. As it happened in the past six years, because of the combination of the size of interest rate movements with the persistence of effects, a double barrel destructive effect on investment and banking, good scenarios tend to be too good, and bad scenarios are seen as terrible for assets markets. An appendix note was written by Thomas Wu on the problem of finding a measurement of the output gap for the Brazilian economy.

Consumer Confidence in Portugal - What does it really matter?

Confidence, in general, and consumer confidence, in particular, are subject to an increasing interest by many agents, such as central banks and governments, at a national level, as well as by supra-national entities, such as the European Commission of the European Union. Although this interest is shared by the academic community, the literature in this area is mainly focussed on the use of consumer confidence to predict variables which describe the business cycle, like consumption. Instead, the objective of our paper is to analyse the evolution of consumer confidence in Portugal and examine which factors underpin its formation. Our empirical study uses monthly data for the period January 1987 — December 2008. We find that consumer confidence, besides presenting some inertia, is basically explained by electoral circumstances.Consumer Confidence, Elections, Portugal

Experimental assessment of RRM techniques in 5 GHz dense WiFi networks using REMs

“© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”The increasing acceptance of WiFi has created unprecedented levels of congestion in the unlicensed frequency bands, especially in densely populated areas. This results mainly because of the unmanaged interference and uncoordinated op- eration between WiFi access points. Radio Environment Maps (REM) have been suggested as a support for coordination strategies that optimize the overall WiFi network performance. In this context, the main objective of this experiment is to assess the benefit of a coordinated management of radio resources in dense WiFi networks at 5 GHz band, using REMs for indoor scenarios. It was shown that REMs can detect the presence of interfering links on the network or coverage holes, and a suitable coordination strategy can use this information to reconfigure Access Points (AP) channel assignment and re-establish the client connection, at a cost of diminishing the aggregate throughput of the network. The technique of AP hand-off was tested to balance the load from one AP to another. Using REMs, the Radio Resource Management (RRM) strategy could reconfigure the network to optimize the client distribution among available APs. Although the aggregate throughput is lower after load balancing, the RRM could increase the throughput of the overloaded AP.info:eu-repo/semantics/publishedVersio

On the globalization of stock markets: An application of VECM, SSA technique and mutual information to the G7?

This paper analyzes the process of stock market globalization on the basis of two different approaches: (i) the linear one, based on cointegration tests and vector error correction models (VECM); and (ii) the nonlinear approach, based on Singular Spectrum Analysis (SSA) and mutual information tests. While the cointegration tests are based on regression models and typically capture linearities in the data, mutual information and SSA are well suited for capturing global non-parametric relationships in the data without imposing any structure or restriction on the model. The data used in our empirical analysis were drawn from DataStream and comprise the natural logarithms of relative stock market indexes since 1973 for the G7 countries. The main results point to the conclusion that significant causal effects occur in this context and that mutual information and the global correlation coefficient actually provide more information on this process than VECM, but the direction of causality is difficult to distinguish in the former case. In this field, SSA shows some advantages, since it enabled us to capture the nonlinear causality in both directions. In all cases, however, there is evidence that stock markets are closely related in the long-run over the 36 years analyzed and, in this sense, one may say that they are globalized.Globalization; Market integration; VECM; Mutual information; SSA technique.

Assessment of 48 Stock markets using adaptive multifractal approach

Stock market comovements are examined using cointegration, Granger causality tests and nonlinear approaches in context of mutual information and correlations. Underlying data sets are affected by non-stationarities and trends, we also apply AMF-DFA and AMF-DXA. We find only 170 pair of Stock markets cointegrated, and according to the Granger causality and mutual information, we realize that the strongest relations lies between emerging markets, and between emerging and frontier markets. According to scaling exponent given by AMF-DFA, $h(q=2)>1$, we find that all underlying data sets belong to non-stationary process. According to EMH, only 8 markets are classified in uncorrelated processes at $2\sigma$ confidence interval. 6 Stock markets belong to anti-correlated class and dominant part of markets has memory in corresponding daily index prices during January 1995 to February 2014. New-Zealand with $H=0.457\pm0.004$ and Jordan with $H=0.602\pm 0.006$ are far from EMH. The nature of cross-correlation exponents based on AMF-DXA is almost multifractal for all pair of Stock markets. The empirical relation, $H_{xy}\le [H_{xx}+H_{yy}]/2$, is confirmed. Mentioned relation for $q>0$ is also satisfied while for $q<0$ there is a deviation from this relation confirming behavior of markets for small fluctuations is affected by contribution of major pair. For larger fluctuations, the cross-correlation contains information from both local and global conditions. Width of singularity spectrum for auto-correlation and cross-correlation are $\Delta \alpha_{xx}\in [0.304,0.905]$ and $\Delta \alpha_{xy}\in [0.246,1.178]$, respectively. The wide range of singularity spectrum for cross-correlation confirms that the bilateral relation between Stock markets is more complex. The value of $\sigma_{DCCA}$ indicates that all pairs of stock market studied in this time interval belong to cross-correlated processes.Comment: 16 pages, 13 figures and 4 tables, major revision and match to published versio

On-light: optical social network

Social networks are a recent phenomenon of communication, with a high prevalence of young users. This concept serves as a motto for a multidisciplinary project, which aims to create a simple communication network, using light as the transmission medium. Mixed team, composed by students from secondary and higher education schools, are partners on the development of an optical transceiver. A LED lamp array and a small photodiode are the optical transmitter and receiver, respectively. Using several transceivers aligned with each other, this con guration creates a ring communication network, enabling the exchange of messages between users. Through this project, some concepts addressed in physics classes from secondary schools (e.g. photoelectric phenomena and the properties of light) are experimentally veri ed and used to communicate, in a classroom or a laboratory

Comportamento alimentar e resistência à inanição de larvas de camarões ornamentais do género Lysmata (Decapoda: Hippolytidae)

Dissertação mest., Biologia Marinha, Universidade do Algarve, 2008The present study describes the effect of starvation on the survival of early zoeal stages of Lysmata amboinensis, L. debelius, L. boggessi, L. seticaudata. Studied species occupy different habitats and exhibit different levels of tolerance to the absence of food. Only newly hatched larvae of L. seticaudata and L. boggessi display facultative primary lecithotrophy, moulting from zoea I to zoea II when starved. All studied species show secondary facultative lecithotrophy on the second zoeal stage, being able to moult to zoea III in the absence of food. Nevertheless, this ability was only recorded in larvae at the second zoeal stage which have not been previously exposed to starvation in zoea I. This is the firts record of secondary facultative lecithotrophy among caridena shrimps. Newly hatched larvae of L. amboinensis, L. debelius, L. ankeri e L. seticaudata show a higher tolerance to starvation periods when kept in the dark, compared to photoperiods with 12 or 24 h of light. This fact may be due to a lower larval energetic consumption as a consequence of a decreased swimming activity. Light exposure is not a determinant factor for prey capture in Lysmata larvae, reinforcing the assumption of decapod crustacean larvae not being active predators. Newly hatched larvae of different studied species ingest similar amounts of Artemia nauplii, while L. ankeri and L. seticaudata are able to capture a higher number of enriched Artemia metanuplii. The comparison of morphological and biometrical larval features do not show a particular pattern, being insufficient to explain the differences recorded in the number of ingested preys. The ability displayed by these organisms to capture and ingest large sized preys (e.g. Artemia metanauplii) opens good perspectives for the use of inert diets during early zoeal stages

Análise da entropia como medida de incerteza e valor ordinal da informação no mercado bolsista de acções português

O problema em estudo neste trabalho de investigação é a possível falta de adequabilidade dos modelos tradicionais utilizados na gestão de carteiras à realidade que caracteriza o mercado bolsista de acções português, principalmente na forma como é avaliada a incerteza neste mercado. A falta de adequabilidade dos modelos está associada ao facto dos mesmos terem como base a distribuição normal das taxas de rendibilidade dos títulos. Este trabalho de investigação visa atingir quatro objectivos. O primeiro objectivo avalia a adequabilidade dos modelos tradicionais de gestão de carteiras ao mercado bolsista português através da análise da distribuição de probabilidade seguida pelas taxas de rendibilidade dos títulos e do índice BVL 30. O segundo objectivo avalia a eficácia da entropia como medida de dispersão e de incerteza face ao desvio-padrão e à variância quando a distribuição empírica não pode ser realmente representada pela distribuição normal. O terceiro objectivo determina as principais vantagens e desvantagens da utilização dos modelos da entropia e informação mútua relativamente aos modelos tradicionais mais utilizados na gestão e selecção de carteiras (média-variância, modelo diagonal de Sharpe e o modelo CAPM), principalmente no que concerne à disponibilização da informação mais credível e completa ao investidor. O último objectivo mostra que a entropia pode ser encarada como medida ordinal do valor da informação