A reappraisal of the evidence on PPP: a systematic investigation into MA roots in panel unit root tests and their implications

Panel unit root tests of real exchange rates – as opposed to univariate tests – usually reject non-stationarity. These tests, however, could be biased if the real exchange rate contained MA roots. Indeed, two independent arguments claim that the real exchange rate, being a sum of a stationary and a non-stationary component, is possibly an ARIMA (1, 1, 1) process. Monte Carlo simulations show, how systematic changes in the parameters of the components, of the test equation and of the correlation matrix affect the size of first and second generation panel unit root tests. Two components of the real exchange rate, the real exchange rate of a single good and a weighted sum of relative prices, are constructed from the data for a panel of countries. Computation of the relevant parameters reveals that panel unit root tests of the real exchange rate are severely oversized, usually much more so than simple ADF tests. Thus, the evidence for PPP from panel unit root tests may be merely due to extreme size biases. --panel unit root test,purchasing power parity,real exchange rate,Monte Carlo simulation

Do banks diversify loan portfolios? A tentative answer based on individual bank loan portfolios

Theory of financial intermediation gives contradicting answers to the question whether banks should diversify or focus their loan portfolios. Our aim is to find out which of the two strategies is predominant in the German banking market. To this end we measure diversification for all German banks in the period from 1993 to 2002. As measures we use a broad set of heuristic approaches which capture the deviation of a bank's portfolio from a specified benchmark. Conceivable benchmarks are naive diversification across all industries or, alternatively, the economy's industry structure. With this framework our analysis comprises the widespread measures of concentration, like the Hirschman-Herfindahl index, but also the less known and in this context innovative group of distance measures. We find that different statistical measures of diversification may indicate contradicting results on the individual bank level. Since distance measures are more appealing from a theoretical point of view, the common practice to rely on measures of concentration only in the debate about diversification and focus, may be misleading. We further find that, despite these differences on the individual bank level, both approaches reveal that the majority of banks significantly increased loan portfolio diversification over the last decade. This tendency is especially driven by the large number of credit cooperatives and savings banks. However, some banks (especially regional banks and subsidiaries of foreign banks) reveal a strategy that seems to be more focused on certain industries. --bank lending,loan portfolio,portfolio theory,diversification,concentration measures,distance measures,focus

Does capital regulation matter for bank behaviour? Evidence for German savings banks

The aim of this paper is to assess how German savings banks adjust capital and risk under capital regulation. We estimate a modified version of the model developed by Shrieves and Dahl (1992). This paper contributes to the literature in three ways. First, we test the capital buffer theory (Marcus 1984, Milne and Whalley 2002). Second, we use dynamic panel data techniques that explicitly take unobserved heterogeneity into account. And third, we provide new evidence for non-US banks by using a new dataset of supervisory data collected by the Deutsche Bundesbank. We find evidence that the coordination of capital and risk adjustments depends on the amount of capital the bank holds in excess of the regulatory minimum (the "capital buffer"). Banks with low capital buffers try to rebuild an appropriate capital buffer by raising capital while simultaneously lowering risk. In contrast, banks with high capital buffers try to maintain their capital buffer by increasing risk when capital increases. These findings support the capital buffer theory. --bank regulation,risk taking,bank capital

Does diversification improve the performance of German banks? Evidence from individual bank loan portfolios

Should banks be diversified or focused? Does diversification indeed lead to enhanced performance and, therefore, greater safety for banks, as traditional portfolio and banking theory would suggest? This paper investigates the link between banks? profitability (ROA) and their portfolio diversification across different industries, broader economic sectors and geographical regions measured by the Herfindahl Index. To explore this issue, we use a unique data set of the individual bank loan portfolios of 983 German banks for the period from 1996 to 2002. The overall evidence we provide shows that there are no large performance benefits associated with diversification since each type of diversification tends to reduce the banks? returns. Moreover, we find that the impact of diversification depends strongly on the risk level. However, it is only for moderate risk levels and in the case of industrial diversification that diversification significantly improves the banks? returns. --focus,diversification,monitoring,bank returns,bank risk

Learning to play 3 x 3 games : neural networks as bounded-rational players

We present a neural network methodology for learning game-playing rules in general. Existing research suggests learning to find a Nash equilibrium in a new game is too difficult a task for a neural network, but says little about what it will do instead. We observe that a neural network trained to find Nash equilibria in a known subset of games, will use self-taught rules developed endogenously when facing new games. These rules are close to payoff dominance and its best response. Our findings are consistent with existing experimental results, both in terms of subject's methodology and success rates

Clinically Relevant Characterization of Lung Adenocarcinoma Subtypes Based on Cellular Pathways: An International Validation Study

Lung adenocarcinoma (AD) represents a predominant type of lung cancer demonstrating significant morphologic and molecular heterogeneity. We sought to understand this heterogeneity by utilizing gene expression analyses of 432 AD samples and examining associations between 27 known cancer-related pathways and the AD subtype, clinical characteristics and patient survival. Unsupervised clustering of AD and gene expression enrichment analysis reveals that cell proliferation is the most important pathway separating tumors into subgroups. Further, AD with increased cell proliferation demonstrate significantly poorer outcome and an increased solid AD subtype component. Additionally, we find that tumors with any solid component have decreased survival as compared to tumors without a solid component. These results lead to the potential to use a relatively simple pathological examination of a tumor in order to determine its aggressiveness and the patient's prognosis. Additional results suggest the ability to use a similar approach to determine a patient's sensitivity to targeted treatment. We then demonstrated the consistency of these findings using two independent AD cohorts from Asia (N = 87) and Europe (N = 89) using the identical analytic procedures

FATORES QUE INTERFEREM NO ROMANTISMO DO ALEITAMENTO MATERNO EXCLUSIVO: UMA REVISÃO INTEGRATIVA

The study has as its object of investigation the factors that interfere in exclusive breastfeeding until the baby's six months of life. The objectives were to highlight the importance of exclusive breastfeeding during this period as recommended by the World Health Organization (WHO) and to verify the factors that contribute to early weaning, as well as what the nursing position should be in view of such a high rate of weaning precocious. The analysis was based on eleven pre-selected articles on breastfeeding for the construction of an integrative review. It was found that there is still a high rate of weaning before the recommended period, even with all the efforts of campaigns carried out on the importance of breastfeeding for various causes, which ends up interfering, in many cases, in the child's health.El estudio tiene como objeto de investigación los factores que interfieren en la lactancia materna exclusiva hasta los seis meses de vida del bebé. Los objetivos fueron resaltar la importancia de la lactancia materna exclusiva durante este período según lo recomendado por la Organización Mundial de la Salud (OMS) y verificar los factores que contribuyen al destete precoz, así como cuál debe ser el puesto de enfermería ante una tasa tan alta. de destete precoz. El análisis se basó en once artículos preseleccionados sobre lactancia materna para la construcción de una revisión integradora. Se encontró que aún existe una alta tasa de destete antes del período recomendado, aun con todos los esfuerzos de las campañas realizadas sobre la importancia de la lactancia materna por diversas causas, lo que termina interfiriendo, muchas veces, en la salud del niño.  O estudo tem como objeto de investigação os fatores que interferem no aleitamento materno exclusivo até os seis meses de vida do bebê. Os objetivos foram ressaltar a importância do aleitamento materno exclusivo durante este período como recomenda a Organização Mundial de Saúde (OMS) e verificar os fatores que contribuem para o desmame precoce, bem como qual deve ser o posicionamento da enfermagem diante de tão alto índice de desmame precoce. A análise baseou-se em onze artigos pré-selecionados sobre o aleitamento materno para a construção de uma revisão integrativa. Constatou-se que ainda há um elevado índice de desmame antes do período recomendado, mesmo com todos os esforços de campanhas realizadas sobre a importância do aleitamento materno por várias causas, o que acaba interferindo, muita das vezes, na saúde da criança

Wilms Tumor Chromatin Profiles Highlight Stem Cell Properties and a Renal Developmental Network

Wilms tumor is the most common pediatric kidney cancer. To identify transcriptional and epigenetic mechanisms that drive this disease, we compared genome-wide chromatin profiles of Wilms tumors, embryonic stem cells (ESCs), and normal kidney. Wilms tumors prominently exhibit large active chromatin domains previously observed in ESCs. In the cancer, these domains frequently correspond to genes that are critical for kidney development and expressed in the renal stem cell compartment. Wilms cells also express “embryonic” chromatin regulators and maintain stem cell-like p16 silencing. Finally, Wilms and ESCs both exhibit “bivalent” chromatin modifications at silent promoters that may be poised for activation. In Wilms tumor, bivalent promoters correlate to genes expressed in specific kidney compartments and point to a kidney-specific differentiation program arrested at an early-progenitor stage. We suggest that Wilms cells share a transcriptional and epigenetic landscape with a normal renal stem cell, which is inherently susceptible to transformation and may represent a cell of origin for this disease