On the statistical estimation of diffusion processes - a partial survey

Data available on continuous-time diffusions are always sampled discretely in time. In most cases, the likelihood function of the observations is not directly computable. This survey covers a sample of the statistical methods that have been developed to solve this problem. We concentrate on some recent contributions to the literature based on three di§erent approaches to the problem: an improvement of the Euler-Maruyama discretization scheme, the employment of Martingale Estimating Functions, and the application of Generalized Method of Moments (GMM).

Changes in test scores distribution for students of the fourth grade in Brazil: a relative distribution analysis for the years 1997 to 2005

To assess the quality of school education, much of educational research is concerned with comparisons of test scores means or medians. In this paper, we shift this focus and explore test scores data by addressing some often neglected questions. In the case of Brazil, the mean of test scores in Math for students of the fourth grade has declined approximately 0,2 standard deviation in the late 1990s. But what about changes in the distribution of scores? It is unclear whether the decline was caused by deterioration in student performance in upper and/or lower tails of the distribution. To answer this question, we propose the use of the relative distribution method developed by Handcock and Morris (1999). The advantage of this methodology is that it compares two distributions of test scores data through a single distribution and synthesizes all the differences between them. Moreover, it is possible to decompose the total difference between two distributions in a level effect (changes in median) and shape effect (changes in shape of the distribution). We find that the decline of average-test scores is mainly caused by a worsening in the position of all students throughout the distribution of scores and is not only specific to any quantile of distribution.

The impact of daycare attendance on math test scores for a cohort of 4th graders in Brazil

We estimate the impact of having attended center-based daycare institutions during early childhood on Math test scores at the 4th grade of elementary school. Because enrollment in daycare centers may depend on unobservable character-istics of the family and the child, we build and estimate a structural model of endogeneous choice of school to deal with the selectivity problem. We nd that attendance to daycare institutions is associated with a gain of approximately 0,04 standard deviation in Math test scores. This result is important to the extent our OLS results as well as most of the studies for Brazil nd no e¤ect associated to daycare attendance, suggesting selectivity may play a role on this finding.

Partial economic reforrns and financial crises: an emerging markets perspective

The recent emerging market experiences have posed a challenge to the conventional wisdom that unsustainable fiscal deficits are the key to understanding financial crises in these countries. The health of the domestic banking system has emerged as the main driving force behind the perverse dynamics of partial reforms. The current paper shares this view and uses a model of contractual inefliciencies in the banking sector to understand the dynamics of these reforms. We find that the threat of a large exchange rate devaluation depends on the stock of international reserves relative to the stock of domestic credit that must be extended by the Central Bank in response to a large capital outflow. Moreover, if a country has a weak banking sector but high net reserve ratios, the capital flow reversal might only increase the vulnerability to a currency crisis without necessarily causing it. The results are in accordance with much of the empiricalliterature on the determinants of financiaI crises in emerging markets. Some aspectsof the recent policy debate on the introduction of capital controls are also analysed.

Does money in schools matter? evaluating the effects of FUNDEF on wages and test scores in Brazil

In this paper we investigate the effects of the 1998 reform in the funding of fundamental education in Brazil (FUNDEF) on the relative wages of public school teachers and on the relative proficiency of public school pupils. The evidence suggests that, on average, FUNDEF raised the public school teachers’ relative wages and improved the relative proficiency of the public school students. Some indirect evidence was presented that showed that the effect of FUNDEF on proficiency seems to be related to its effect on wages and on school characteristics. The effect on proficiency seems to be concentrated in the municipal schools in the Northeast of the country.

Assessorias e coberturas jornalísticas na administração pública municipal

O objetivo dessa dissertação consiste em analisar a interação entre assessorias de imprensa de prefeituras brasileiras e jornais locais. Para tal, dois municípios são analisados, observando a relação existente entre as assessorias e os veículos. É verificado, por exemplo, a frequência com que estes publicam releases governamentais em suas páginas, o que fornece um indício chave do grau de independência da mídia local. Apresentam-se dois estudos de caso, realizado com as cidades de Bauru e Piracicaba - que, além de serem cidades prósperas, localizadas no interior do Estado de São Paulo, apresentam diversas características que as aproximam, como: número de habitantes, orçamento municipal, PIB e IDH - permitindo comparar e analisar a relação das assessorias de comunicação de suas prefeituras, com um jornal impresso local diário, de cada uma das cidades. Embasa o trabalho na teoria do agenda setting, e da relação entre mídia e democracia. Procura-se compreender ainda, de acordo com a literatura, os outros papéis da mídia, como watchdog e gatekeeper. A pesquisa demonstra que existe alto grau de correspondência na cidade de Bauru, onde 48% das vezes em que o Jornal da Cidade veiculou matérias relacionadas a prefeitura, ele o fez aproveitando de forma integral, ou parcial (com pequenas alterações), os releases enviados pela assessoria de comunicação da prefeitura. Já no caso de Piracicaba, apenas 5% das vezes em que o Jornal de Piracicaba veiculou matérias relacionadas à prefeitura, ele o fez aproveitando de forma integral, ou parcial (com pequenas alterações), os releases enviados pela assessoria de comunicação da prefeitura. Quando publica matérias sobre a prefeitura, o Jornal de Piracicaba publica matérias com 1773 caracteres, em média. Enquanto o Jornal da Cidade apresenta uma média de 2453 caracteres.