Who Benefits from Reducing the Cost of Formality? Quantile Regression Discontinuity Analysis

This paper studies the effects of increasing formality via tax reduction and simplification schemes on micro-firm performance. It uses the 1997 Brazilian SIMPLES program. We develop a simple theoretical model to show that SIMPLES has an impact only on a segment of the micro-firm population, for which the effect of formality on firm performance can be identified, and that can be analyzed along the single dimensional quantiles of the conditional firm revenues. To estimate the effect of formality, we use an econometric approach that compares eligible and non-eligible firms, born before and after SIMPLES in a local interval about the introduction of SIMPLES. We use an estimator that combines both quantile regression and the regression discontinuity identification strategy. The empirical results corroborate the positive effect of formality on microfirms' performance and produce a clear characterization of who benefits from these programs.Formality, Micro-firms, Quantile regression, Regression discontinuity

In search of meta-knowledge

Development of an Intelligent Information System (IIS) involves application of numerous artificial intelligence (AI) paradigms and advanced technologies. The National Aeronautics and Space Administration (NASA) is interested in an IIS that can automatically collect, classify, store and retrieve data, as well as develop, manipulate and restructure knowledge regarding the data and its application (Campbell et al., 1987, p.3). This interest stems in part from a NASA initiative in support of the interagency Global Change Research program. NASA's space data problems are so large and varied that scientific researchers will find it almost impossible to access the most suitable information from a software system if meta-information (metadata and meta-knowledge) is not embedded in that system. Even if more, faster, larger hardware is used, new innovative software systems will be required to organize, link, maintain, and properly archive the Earth Observing System (EOS) data that is to be stored and distributed by the EOS Data and Information System (EOSDIS) (Dozier, 1990). Although efforts are being made to specify the metadata that will be used in EOSDIS, meta-knowledge specification issues are not clear. With the expectation that EOSDIS might evolve into an IIS, this paper presents certain ideas on the concept of meta-knowledge and demonstrates how meta-knowledge might be represented in a pixel classification problem

Characterization of Vesicular Monoamine Transporter 2 and its role in Parkinson\u27s Disease Pathogenesis using Drosophila

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the selective loss of the dopaminergic neurons in the Substantia nigra pars compacta region of the brain. PD is also the most common neurodegenerative disorder and the second most common movement disorder. PD patients exhibit the cardinal symptoms, including tremor of the extremities, rigidity, slowness of movement, and postural instability, after 70-80% of DA neurons degenerate. It is, therefore, imperative to elucidate the underlying mechanisms involved in the selective degeneration of DA neurons. Although increasing numbers of PD genes have been identified, why these largely widely expressed genes induce selective loss of DA neurons is still not known. Notably, dopamine (DA) itself is a chemically labile molecule and can become oxidized to toxic by-products while induce the accumulation of harmful molecules such as Reactive Oxygen Species (ROS). Accordingly, DA toxicity has long been suspected to play a role in selective neuronal loss in PD. Vesicular Monoamine Transporter (VMAT) is essential for proper vesicular storage of monoamines such as DA and their regulated release. Increasing evidence have linked VMAT dysfunction with Parkinson’s disease. In this study, we re-examine the gain- and loss-of-function phenotypes of the sole VMAT homologue in Drosophila. Our results suggest that the C-terminal sequences in the two encoded VMAT isoforms not only determine their differential subcellular localizations, but also their activities in content release. In particular, VMAT2 orthologue potentially poses a unique, previously unexplored activity in promoting DA release. On the other hand, by examining DA distribution in wildtype and VMAT mutant animals, we find that there exists intrinsic difference in the dynamics of intracellular DA handling among DA neurons clustered in different brain regions. Furthermore, loss of VMAT causes severe loss of total DA levels and a redistribution of DA in Drosophila brain. Lastly, removal of both VMAT and another PD gene parkin, which is also conserved in Drosophila, results in the selective loss of DA neurons, primarily in the protocerebral anterior medial (PAM) clusters of the brain. Our results suggest a potential involvement of cytoplasmic DA in selective degeneration of DA neurons and also implicating a role for a differential intracellular DA handling mechanism underlying the regional specificity of neuronal loss in PD patients

The Self-insurance Role of International Reserves and the 2008-2010 Crisis

There is no standard rule for the definition of an “optimal level” of international reserves and several assumptions underlie the rationale behind holding reserves. There are various theoretical approaches, but no standard for the evaluation of the performance of “optimal level” models, and their parameters are difficult to estimate. The literature suggests that the benefits of holding reserves are high, but the accumulation of reserves is a costly strategy. In fact, in a world of high liquidity and free capital flow, establishing an adequate level of international reserves is still a puzzle. The strategy of accumulating international reserves is evaluated here using data from the 2008-2010 crisis and it is shown that countries with higher international reserve levels had less adjustment costs between 2008 and 2010. The cost-benefit relationship of holding reserves in the 2008-2010 crisis is also discussed based on a sample with 71 countries.