nÃo hà / Este estudo compreende duas anÃlises para investigar alguns cenÃrios especÃficos sobre os rendimentos de trabalhadores brasileiros. A primeira trata de investigar os principais determinantes dos rendimentos dos filhos, dentre os quais a ocorrÃncia de transmissÃo das rendas dos pais. EstimaÃÃes de equaÃÃes de rendimentos com distintos procedimentos metodolÃgicos permitem captar o efeito transmissÃo (heranÃa familiar) e o efeito dinÃmico (anÃlise de geraÃÃes superpostas), cujas verificaÃÃes empÃricas sÃo baseadas nos dados da Pesquisa Nacional por Amostra de DomicÃlios (PNAD) para os anos de 1989 e 2009. SÃo utilizados os mÃtodos de Heckman em dois estÃgios e o modelo de variÃveis instrumentais, haja vista a necessidade de correÃÃo do viÃs de seleÃÃo amostral e a endogeneidade presente em equaÃÃes de rendimentos. AlÃm destes, aplica-se o mÃtodo KleinâVella, por ser um procedimento corretivo para se obter o verdadeiro efeito mÃdio, e nÃo apenas um efeito para os indivÃduos que sÃo realmente afetados por variaÃÃes nos instrumentos. Em seguida, devido à impossibilidade de se obter contrafactuais perfeitos nos dados da PNAD, estimam-se regressÃes quantÃlicas no sentido de aumentar o grau de confiabilidade nas estimativas atravÃs da homogeneizaÃÃo dos trabalhadores na amostra por faixas de rendimento. Das alternativas metodolÃgicas, constatou-se que o mÃtodo de variÃveis instrumentais apresentou o pior ajuste preditivo. Quanto Ãs demais abordagens, suas estimativas nÃo permitiram concluir haver superioridade estatÃstica de uma sobre a outra para fins de inferÃncia. Portanto, pode-se concluir a partir destas que as rendas dos pais, principalmente a renda da mÃe, exercem um impacto positivo e significante de transmissÃo sobre as rendas dos seus filhos. Apesar da comprovaÃÃo do efeito de transmissÃo de renda, este se mostrou com tendÃncia declinante ao longo do tempo. A segunda anÃlise visa testar possÃveis diferenÃas de rendimentos por gÃnero em trÃs nÃveis regionais (Brasil, Nordeste e Sul-Sudeste) e quatro nÃveis ocupacionais (todas as ocupaÃÃes, dirigentes, serviÃos e tÃcnicos). Para tanto, foram avaliados trÃs enfoques metodolÃgicos para estimaÃÃes da equaÃÃo minceriana de rendimentos. Primeiramente avaliam-se os mÃtodos de MÃnimos Quadrados OrdinÃrios e de Heckman em dois estÃgios para corrigir o viÃs de seleÃÃo. Para testar a existÃncia de discriminaÃÃo por gÃnero no mercado de trabalho emprega-se o mÃtodo de Propensity Score Matching. Para inferir sobre tal discriminaÃÃo aplica-se o mÃtodo OaxacaâBlinder, o qual permite decompor as diferenÃas salariais devidas Ãs caracterÃsticas individuais (explicada) e à discriminaÃÃo (nÃo explicada). Independentemente do mÃtodo utilizado nas estimaÃÃes realizadas, comprova-se que existe diferenÃa salarial a favor dos homens, cuja superioridade varia de 36,32% (Dirigentes no Brasil) a 118,72% (TÃcnicos no Nordeste). AlÃm disso, conclui-se que tal diferenÃa à resultado da presenÃa de discriminaÃÃo por gÃnero, uma vez que, em todas as estimaÃÃes realizadas, o efeito da discriminaÃÃo, o qual varia de 100,5% (ServiÃos no Sul-Sudeste) a 153,8% (TÃcnicos no Brasil), à maior que a diferenÃa dos rendimentos, pois as mulheres tÃm, em mÃdia, atributos adquiridos (escolaridade, por exemplo) superiores aos dos homens. Portanto, caso nÃo houvesse discriminaÃÃo, hà evidÃncias na amostra utilizada de que os rendimentos das mulheres tenderiam a ser, em mÃdia, superiores aos dos homens.

Submitted by Marcello Barreto (mbarreto@cbab.com.br) on 2012-08-02T19:43:46Z No. of bitstreams: 1 Dissertacao Marcello Barreto - Versão Final - 02-08.pdf: 1121539 bytes, checksum: d24a321be480e9de11d37f89b5312e4d (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2012-08-03T18:32:20Z (GMT) No. of bitstreams: 1 Dissertacao Marcello Barreto - Versão Final - 02-08.pdf: 1121539 bytes, checksum: d24a321be480e9de11d37f89b5312e4d (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2012-08-07T20:31:25Z (GMT) No. of bitstreams: 1 Dissertacao Marcello Barreto - Versão Final - 02-08.pdf: 1121539 bytes, checksum: d24a321be480e9de11d37f89b5312e4d (MD5) / Made available in DSpace on 2012-08-07T20:31:33Z (GMT). No. of bitstreams: 1 Dissertacao Marcello Barreto - Versão Final - 02-08.pdf: 1121539 bytes, checksum: d24a321be480e9de11d37f89b5312e4d (MD5) Previous issue date: 2012-06-27 / The main objective of this dissertation is to investigate the impact of accruals on the corporate earnings variability (EVAR) results that influence the practical application of income smoothing in Brazilian capital market firms. Initially, it approaches the importance of financial statements that must be evidenced in compliance with accounting principles generally accepted. Its disclosure should represent the reality of the economic-financial firm to the process of decision-making of shareholders and creditors. But at certain times, managers are motivated to practice the earnings management in an attempt to reduce the variability of profits through the use of accruals. The accruals represent the difference between net income and operating cash flow. In the process for reducing results volatility managers use the practice of income smoothing that represents a smoothing of profits, reducing any distortions in the market price of the firm. In this study, the sample is formed by a group of 163 capital market firms listed on Bovespa and presenting financial information in the period 2000 to 2007, categorized by sector, using data obtained in Economática. The statistical model used for this research was the regression analysis in order to explain the different cross-sectional models. These survey results indicate that accruals are significant to explain the EVAR of Brazilian companies. Our results suggest that the identification of structural model corporate earnings variability (EVAR) in Brazilian companies should be evidenced by non-financial variables that differ from those made by U.S. firms. / Esta dissertação tem como objetivo principal investigar o impacto dos accruals na variabilidade dos resultados corporativos (EVAR) que influenciam a aplicação prática do income smoothing nas firmas brasileiras de capital aberto. Inicialmente, é demonstrada a importância das demonstrações contábeis que devem ser evidenciadas em cumprimento aos princípios contábeis geralmente aceitos. Sua evidenciação deve representar a realidade econômico-financeira da firma para o processo de tomada de decisão dos acionistas e credores. Porém, em determinados momentos, os gestores se sentem motivados a praticar o gerenciamento dos resultados contábeis na tentativa de reduzir a variabilidade dos lucros por meio da utilização dos accruals. Os accruals correspondem à diferença entre o lucro líquido e o fluxo de caixa operacional. Nesse processo de redução da volatilidade dos resultados, os gestores se utilizam da prática do income smoothing procurando reduzir eventuais distorções no preço das ações da firma. A amostra neste estudo é composta por um grupo de 163 firmas de capital aberto listadas na Bovespa e que apresentaram informações financeiras no intervalo de 2000 a 2007, categorizadas por setores através de dados obtidos na Economática. O modelo estatístico utilizado na pesquisa foi a análise de regressão para explicar os diferentes modelos de cross-sectional. Os resultados desta pesquisa indicam que os accruals são significativos para explicar a variabilidade dos resultados corporativos (EVAR) de empresas brasileiras. Além disso, nossos resultados sugerem que o modelo estrutural de identificação do EVAR nas empresas brasileiras deve ser explicado por variáveis não contábeis diferentes das que são apresentadas pelas firmas norte-americanas.

Les objectifs de notre thèse sont d'étudier les évolutions du marché du travail depuis Doï Moï (la réforme économique au VN en 1986) et les impacts de l'intégration internationale de l'économie du Vietnam, en mettant l'accent sur une distinction des secteurs formel et informel. Dans notre thèse, nous étudions les impacts de la libéralisation commerciale et l'augmentation des salaires minimums dans les secteurs domestiques. Ce dernier peut également être considéré comme un facteur relatif à l'intégration internationale puisqu'il a suivi les engagements du Vietnam dans le cadre de l'adhésion à WTO. Pour les impacts de la libéralisation commerciale, nous examinons les effets sur les allocations de main-d'œuvre entre différents types d'emplois, y compris le travail salarié dans les secteurs formels et les entreprises ménagères, ainsi que les emplois autonomes dans les secteurs manufacturiers. Les impacts sur les écarts de revenus dans les différents types d'emplois sont également exploités. Pour les impacts de l'augmentation des salaires minimums, nous exploitons les effets sur le total des emplois, les mouvements entre les secteurs formels et les autres types d'emplois, la répartition des salaires dans les secteurs formel et informel et les écarts de salaire entre les deux secteurs à différents centiles. Chapitre 1. Libéralisation commerciale, allocation du travail et dynamique des revenus au Vietnam Abstrait Cette étude vise à répondre à deux questions inter-liées au Viet Nam: (i) comment la libéralisation commerciale influence l'allocation des travailleurs, entre travail indépendant, travail salarié dans les entreprises familiales et le travail salarié dans le secteur formel (entreprises privées, étrangères et publiques); et (ii) les écarts de revenus entre ces types d'emplois. Une extension du modèle « deux étapes » de Goldberg et Pavcnik (2003) et sa modification sont utilisées pour répondre aux questions. Les données proviennent de cinq enquêtes traditionnelles sur le vieillissement du ménage du Viet Nam de 2002 à 2010 et des mesures disponibles de la libéralisation commerciale au Viet Nam. Les résultats indiquent que la libéralisation commerciale n'a pas d'impact significatif sur les écarts de revenus entre les types d'emplois. Parallèlement, les augmentations de l'exposition au commerce international réduisent les salaires dans les entreprises familiales, par rapport à celles des secteurs formels. L'augmentation de la libéralisation commerciale a également des répercussions sur les emplois autonomes, mais il semble que les orientations des impacts dépendent des statuts de l'importation nette ou de l'exportation nette d'industries du Viet Nam. Chapitre 2. Impacts de l'unification des salaires minimum entre les secteurs sur les allocations de travail et la dynamique des revenus au Vietnam Abstrait Les taux de salaire minimum au Viet Nam ont augmenté considérablement depuis 2009 en tant qu'engagements d'unification entre les IDE et les secteurs domestiques dans le cadre de l'adhésion à WTO. Cette croissance a été considérée comme supérieure à la croissance de la productivité de l'économie. En utilisant les données des Enquêtes sur la population active du Vietnam et les enquêtes sur le niveau de vie des ménages de 2010 à 2014, le document actuel examine les répercussions des salaires minimum sur les statuts de l'emploi, la répartition des salaires dans les secteurs formel et informel ainsi que les écarts de salaire entre les deux secteurs. Les résultats impliquent que le salaire minimum n'a pas d’effet significatif sur l'ensemble des emplois de l'ensemble de la population. Ce résultat est quelque peu différent de ceux rapportés dans des études antérieures pour le Viet Nam. / The objectives of the current thesis are to investigate evolutions of the labor market since Doi Moi and impacts from the international integration of Vietnam’s economy, with focuses on a distinction of formal and informal sectors. In the current state of the thesis, the impacts of the trade liberalization and the increases in the minimum wages of the domestic sectors are studied. Indeed, the latter factor, the increase in the minimum wages, can be also considered as a factor relating to the international integration as it followed Viet Nam’s commitments under the WTO accession. For the impacts of the trade liberalization, the thesis investigates the impacts on labor allocations between different types of employments including wage work in the formal sectors and household businesses as well as self-employments in manufacturing sectors. The impacts on income differentials across the types of employments are also exploited. For the impacts of the increases in the minimum wages, the thesis exploits the effects on the total employments, movements between the formal sectors and other types of employments, wage distributions within the formal and informal sectors and wage gaps between the two sectors at different percentiles. Chapter 1. Trade liberalization, labor allocation and income dynamics in Vietnam Abstract This study seeks to answer two inter-related questions for Viet Nam: (i) how trade liberalization affects the allocation of workers across self-employment, wage work in household businesses and wage work in the formal sector (private, foreign invested and state enterprises); and (ii) income differentials between these kinds of employment. An extension of the two-step model in Goldberg and Pavcnik (2003) and its modification are employed to answer the questions. Data is sourced from five Viet Nam Household Living Standard Surveys from 2002 to 2010 and available measures of the trade liberalization in Viet Nam. The results indicate that the trade liberalization does not have significant impacts on income differentials between types of employments. Meanwhile, increases in exposing to the international trade reduce wage works in household businesses, compared with that in the formal sectors. The increase in the trade liberalization also has impacts on self-employments but it seems that the directions of impacts depend on statues of net import or net export of industries of Viet Nam. Chapter 2. Impacts of unification of minimum wages across sectors on labor allocations and income dynamics in Vietnam Abstract Rates of minimum wages in Viet Nam have increased drastically since 2009 as commitments of unification between those in FDI and domestic sectors under the WTO accession. This growth has been considered as being higher to productivity growth of the economy. Employing data of Vietnam Labor Force Surveys and Household Living Standard Surveys from 2010 to 2014, the current paper investigates impacts of the minimum wages on employment statues, wage distributions in formal and informal sectors as well as wage gap between the two sectors. The results imply that the minimum wages do not have significant impacts on the total employments of the whole population. This result is somewhat different from those reported in previous studies for Viet Nam. Our different specifications detect that the differences in the results are attributed to inclusions of trends in studying. Similar to the work of Hansen et al. (2015), the results indicates that that the minimum wages positively affects the wage distribution in the formal sectors. However, we find that the effects do not stop at the median as the result of Hansen et al. but also on higher percentiles. Finally, the minimum wages increases the wage gap between the formal and informal sectors with stronger effects at higher percentiles of the wage distribution.

This paper evaluates the ability of single and multi-ratio investment strategies, such as P/E, P/B, Magic Formula and Piotroski F-score, to generate excess returns and positive alpha values on the Stockholm Stock Market. Performances of the strategies tested are compared to the Stockholm Stock Market as a whole, also known as the index “OMXSPI”. In this paper, three single-ratio strategies are investigated along with three multi-ratio strategies, chosen on the basis of popularity among private investors, according to our observations. We also compare these strategies’ returns to the returns of the ten best performing funds, over the last ten years, found on SEB’s and Handelsbanken’s fund lists. We find that both multi and single-ratio strategies generated alpha values and that single-ratio strategies performed well, relative to multi-ratio strategies, considering their simplicity. The current portfolio composition from screening stocks based on low P/E, P/B and high dividend yield alone are also associated with less risk, expressed in volatility, than portfolios that would be composed based on the multi-ratio methods. We even find that one of the more complex strategies, Graham Screener, underperformed single-ratio strategies, when comparing yearly alpha values over 15 and 17 years, respectively. The funds’ alpha values are also very poor compared to both single and multi-ratio strategies considering the managers’ likely investment experience and complex investment systems. In sum, our empirical data suggests that excess returns were indeed attainable during the investigated time-periods by following a rule-based investing philosophy in conjunction with single or multi-ratio strategies, and unless the investor has sublime experience and knowledge, he or she is probably better off using this type of investing rather than making investment decisions in a discretionary manner.We also conclude that the Stockholm Stock Market probably suffered from lower market efficiency, from the perspective of the Efficient Market Hypothesis, and lower screening abilities and tools, such as Börsdata, among investors in the beginning of the testing periods, which could be one reason as to why these ratio strategies worked as well as they did. However, the results are still interesting because complexity does not seem to imply value (extra alpha generation) of significant magnitude, if at all. What does seem to imply value, are the minimization of human interactions with investment models and emotional stability.

本研究的目的在比較研究中國大陸與台灣股市，其上市公司的財務資訊特性，以及這些財務資訊在這兩個股市中的有用性。大陸股市迄今年齡尚輕，僅七歲。唯大陸股市的法規，散戶多，同文同種等與台灣股市相近；不同之處在於，例如國家對上市公司所持有的股份仍佔一定比例、法人極少（中國大陸自五月份始方開放共同基金的發行）、股市分為 A、B 及 H 股等。因此在不同的股市特性及股市環境下，到底公開資訊被使用的情形如何？這種比較分析可令我們深入瞭解，在不同股市特性及股市環境（包括證劵管理環境）下，投資者使用公開財資訊的深度與廣度。因此本研究以公開財務報表為例，探討並比較台灣股市與中國大陸間資訊有用性及有用程度。 本研究採用傳統盈餘／股價關係的研究設計來探討其間的關係，根據　Easton and Harris(1991)及 Lev(1989)的建議，在傳統的盈餘反應係數模式中加入二個與盈餘相關變數，一為「當期盈餘水準除以期初股價」的盈餘水準變數；另一為「當期盈餘變動除以期初股價」的未預期盈餘變數，以此二盈餘變數實證比較兩岸股市，其相對盈餘資訊內涵。其次，依據 Lipe(1986)的建議及其所建立的實證模式，本研究測試盈餘組成分子是否具備增額資訊內涵，並比較兩岸盈餘組成分子增額資訊內涵是否顯著不同。最後，本研究借用 ERC 模式，並依據 Collins and kothari(1989)加入 ERC 決定因素如公司系統風險、盈餘持續度、公司成長機會等，來增進盈餘／股會間關係的解釋能力，以期在最具解釋力的模式下，比較兩盈餘資訊內涵。本研究台灣方面以台灣證劵交所股票上市公司為對象，研究期間自民國 77 年至 85 年止，共計 9 年為樣本期間，大陸則以在上海、深圳交易所上市的股票上市公司樣本，研究期間則為 1994 年至 1996 年研究結果顯示： 1.兩岸之資訊環境存在顯著差異性。 2.兩岸之盈餘資訊皆具有用性。 3.盈餘組成項目均具增額資訊內涵。 4.考慮 ERC 模式後可增加模式之解釋力。 / This study mainly applies ERC (Earnings Response Coefficient) model to compare the information contents of earnings in Taiwan and China stock markets. In addition, this study investigates the disclosure rules of these two markets in order to develop related hypotheses. This study includes four hypotheses: (1) information environment hypothesis, (2) earning level hypothesis, (3) earnings components hypothesis, and (4) ERC determinants hypothesis. The samples strategically select from. listed companies in Taiwan and China to facilitate our comparisons. The findings can be summarized as follows. 1. In the Taiwan stock market, the firm size is not a significant factor for determining optimal return window; but in the China stock market, the response of larger firms is earlier than smaller firms to the earnings announcement (information environment hypothesis). 2. The Easton-Harris earnings level variable can significantly increase the explanatory power of ERC in the Taiwan stock market; but it cannot significantly increase the explanatory power of ERC in the China stock market (earnings level hypothesis). 3. The earnings components can increase the explanatory power of earnings/return relationship in both Taiwan and China stock markets. In addition, the non-operating components have better explanatory power than operating components in earnings (earnings components hypothesis). 4. The determinants of ERC can increase the explanatory power of earnings/return relationship; but the determinants of ERC have negative effects of the explanatory power of earnings/return relationship.

現今，世界經濟脈動迅速，科技發展日新月異，如何在瞬息萬變的趨勢洪流中掠取先機，端賴自身競爭力強弱而定。然而管理當局短視行為的發生，卻易損及企業的競爭優勢，甚至對企業未來有不利影響。造成管理當局短視之因源於多方面，來自資本市場投資人的影響即為其一。而資本市場中，機構投資人往往是大家注目的焦點，因此本研究乃對機構投資人持股比例與管理當局短視行為的關係進行探討，並期望能對公司治理制度的擬定上有所助益。 本研究以民國八十四年至民國九十年為研究期間，針對我國上市公司研究其管理當局短視行為與機構投資人持股比例間的關係，並探究在電子與非電子產業間兩者關係是否相同。此外，本研究亦比較機構投資人與個人投資者，各自持股比例與管理當局短視行為的相關情形，進以探尋真正能發揮監理機制的投資人類別。 實證結果顯示：(1)管理當局短視行為與機構投資人持股比例高低有顯著之負向關係，而與個人投資者持股比例間則有顯著的正向關係。(2)在非電子產業中，機構投資人持股與管理當局短視行為呈顯著負向關係，而電子產業中兩者則無顯著關係。(3)管理當局短視行為與機構投資人持股比例變動的幅度有顯著之負向關係，而與個人投資者持股比例變動則有顯著的正向關係。(4)在非電子股產業方面，機構投資人持股比例變動幅度與管理短視行為間無顯著關係；但在電子產業中，則兩者間呈現顯著之負向關係。 / Nowadays, the economy situation is changing so fast and the development of new technology has altered with each passing day. To be ahead of their competitors, firms must sharpen their competitive edge. However, management myopia often damage their competitive advantages and would do harm to the firms in the future. The phenomenon of management myopia is derived from many reason, one of them is the effect of the investors in the capital market. Furthermore, participants in the capital market always pay attention to the behavior of institution investors. Thus, this research explores the relationships between the ownership of institution investors and management myopic. We hope it would be beneficial to the enactment of the system of corporate governance. This research focuses on the relationship between the myopic behavior of management and the ownership of institution investors of the listed companies in Taiwan Stock Exchange from 1995 to 2001. It also explores if the relationship is the same in both electronic industry and non-electronic industries. Besides, the study also compares the effect of the ownership of individual or institution investors on the management myopia in order to point out the type of investors that can provide monitory function clearly. The empirical study indicates that (1) there is a significant negative relationship between the myopic behavior of management and the ownership of institution investors. Conversely, there is a significant positive relationship between the myopic behavior of management and the ownership of individual investors. (2) In the electronic industry, the relationship between the ownership of institution investors and the myopic behavior of management is not significant. However, it is significant negative in other industries. (3) The change of percentage of ownership of institution investors has significant negative relationship with the management myopia. However, it is opposite to the individual investors. (4) No significant relationship between the institution investors and the management myopic in non-electronic industries. But in the electronic industry, it is significant negative.

Dans ma thèse, je me sers de modèles de recherche solides pour répondre à des questions importantes de politique publique. Mon premier chapitre évalue l’impact causal de l’allégeance partisane (républicain ou démocrate) des gouverneurs américains sur le marché du travail. Dans ce chapitre, je combine les élections des gouverneurs avec les données du March CPS pour les années fiscales 1977 à 2008. En utilisant un modèle de régression par discontinuité, je trouve que les gouverneurs démocrates sont associés à de plus faibles revenus individuels moyens. Je mets en évidence que cela est entrainée par un changement dans la composition de la main-d’oeuvre à la suite d’une augmentation de l’emploi des travailleurs à revenus faibles et moyens. Je trouve que les gouverneurs démocrates provoquent une augmentation de l’emploi des noirs et de leurs heures travaillées. Ces résultats conduisent à une réduction de l’écart salarial entre les travailleurs noir et blanc. Mon deuxième chapitre étudie l’impact causal des fusillades qui se produisent dans les écoles secondaires américaines sur les performances des éléves et les résultats des écoles tels que les effectifs et le nombre d’enseignants recruté, a l’aide d’une stratégie de différence-en-différence. Le chapitre est coécrit avec Dongwoo Kim. Nous constatons que les fusillades dans les écoles réduisent significativement l’effectif des élèves de 9e année, la proportion d’élèves ayant un niveau adéquat en anglais et en mathématiques. Nous examinons aussi l’effet hétérogene des tueries dans les écoles secondaires entre les crimes et les suicides. Nous trouvons que les fusillades de natures criminelles provoquent la diminution du nombre d’inscriptions et de la proportion d’élèves adéquats en anglais et mathématiques. En utilisant des données sur les élèves en Californie, nous confirmons qu’une partie de l’effet sur la performance des élèves provient des étudiants inscrits et ce n’est pas uniquement un effet de composition. Mon troisième chapitre étudie l’impact des cellulaires sur la performance scolaire des élèves. Le chapitre est coécrit avec Richard Murphy. Dans ce chapitre, nous combinons une base de données unique contenant les politiques de téléphonie mobile des écoles obtenues à partir d’une enquète auprès des écoles dans quatre villes en Angleterre avec des données administratives sur la performance scolaire des éleves. Nous étudions ainsi l’impact de l’introduction d’une interdiction de téléphonie mobile sur le rendement des éleves. Nos résultats indiquent qu’il y a une augmentation du rendement des éleves après l’instauration de l’interdiction des cellulaires à l’école, ce qui suggère que les téléphones mobiles sont sources de distraction pour l’apprentissage et l’introduction d’une interdiction à l’école limite ce problème. / In my thesis, I use compelling research designs to address important public policy issues. My first chapter estimates the causal impact of the party allegiance (Republican or Democratic) of U.S. governors on labor market outcomes. I match gubernatorial elections with March CPS data for income years 1977 to 2008. Using a regression discontinuity design, I find that Democratic governors are associated with lower average individual earnings. I provide evidence that this is driven by a change in workforce composition following an expansion in employment of workers with low and medium earnings. I also find that Democratic governors cause a reduction in the racial earnings gap between black and white workers through an increase in the annual hours worked by blacks relative to whites. My second chapter analyze how shootings in high schools affect schools and students using data from shooting databases, school report cards, and the Common Core of Data. The chapter is co-written with Dongwoo Kim. We examine schools’ test scores, enrollment, and number of teachers, as well as graduation, attendance, and suspension rates at schools that experienced a shooting, employing a difference-in-differences strategy that uses other high schools in the same district as the comparison group. Our findings suggest that homicidal shootings significantly decrease the enrollment of students in Grade 9, and reduce test scores in math and English. We find no statistically significant effect for suicidal shootings on any outcome variables of interest. Using student-level data from California, we confirm that some of the effects on student performance occur as a result of students remaining enrolled and not only due to changes in student body composition. My third chapter investigates the impact of school mobile phone policy on student performance. The chapter is co-written with Richard Murphy. Combining a unique dataset on autonomous mobile phone policies from a survey of schools in four cities in England with administrative data, we investigate the impact of imposing a mobile phone ban on student performance. Our results indicate an improvement in student results after a school bans the use of mobile phones; this suggests that mobile phones distract learning and imposing a ban limits this problem.

Made available in DSpace on 2016-04-25T18:40:01Z (GMT). No. of bitstreams: 1 Geraldo Carlos Silvestre.pdf: 2013597 bytes, checksum: 8ffc3c06da529b4abcc3d44e6dbe94bd (MD5) Previous issue date: 2014-06-27 / In Brazil, in 2007, the first educational traded companies, Anhanguera, Estácio and Kroton, surrounded by high expectations of positive future results and high and quick returns to investors emerged. After more than six years of IPO emerges the question as to the financial performance of these institutions. Thus, the present study aimed to investigate and analyze the financial performance of the universe (N = 3) of the Higher Education Institutions (HEI) traded in the period 2007-2013, using the indicators: i) value creation measured by EVA; ii) ability to cash generation measured by EBITDA; and iii) financial situation evaluated by the Fleuriet method. Based on secondary sources of data and document analysis in the public domain were calculated, analyzed and compared the performance of HEIs. The results showed that all three have solid financial situation but with a major difference in the ability to generate cash. In the period 2007-2013, only Estácio generated shareholder value. Kroton destroyed / consumed shareholder value during the study period, however, initiated a recovery process in 2012 and in 2013, after six years destroying / consuming value for the first time generated shareholder value. Anhanguera destroyed / consumed shareholder value during the seven years. The results also revealed that financial performance is highly dependent on governmental policies on access and funding of higher education and has directly influenced the market value of the traded HEI / No Brasil, em 2007, surgiram as primeiras empresas educacionais de capital aberto, Anhanguera, Estácio e Kroton, cercadas por grandes expectativas de resultados futuros positivos e de elevados e rápidos retornos aos investidores. Passados mais de seis anos da abertura de capital emerge a questão quanto ao desempenho econômico-financeiro dessas instituições. Dessa forma, o presente estudo teve como objetivo apurar e analisar o desempenho econômico-financeiro do universo (N = 3) das Instituições de Ensino Superior (IES) de capital aberto, no período de 2007 a 2013, utilizando os indicadores de: i) geração de valor mensurado pelo EVA; ii) capacidade de geração de caixa mensurada pelo EBITDA; e iii) situação financeira avaliada pelo Método Fleuriet. Com base em fontes de dados secundários e análise documental de domínio público foram apurados, analisados e comparados os desempenhos das IES. Os resultados demonstraram que as três apresentam situação financeira sólida mas com uma grande divergência na capacidade de geração de caixa. No período de 2007 a 2013, apenas a Estácio gerou valor para os acionistas. A Kroton, destruiu/consumiu valor dos acionistas no período de estudo, entretanto, iniciou um processo de recuperação em 2012 e em 2013, após seis anos destruindo/consumindo valor, pela primeira vez gerou valor aos acionistas. A Anhanguera destruiu/consumiu valor dos acionistas durante os sete exercícios. Os resultados também revelaram que o desempenho econômico-financeiro é altamente dependente das políticas governamentais de acesso e financiamento do ensino superior e tem influenciado diretamente no valor de mercado das IES

Os artigos científicos são o principal veículo de comunicação para divulgação dos resultados obtidos por milhares de pesquisadores ao redor do mundo. Entretanto, escrever os artigos científicos em publicações de alto impacto é uma tarefa complexa para autores que têm o inglês como segunda língua. Por meio da aprendizagem baseada em exemplos e em experiência, as habilidades de leitura, interpretação e redação de textos científicos podem ser desenvolvidas por intermédio da prática, facilitada por meio de exemplos de trechos de texto reutilizáveis. Para auxiliar na redação de artigos, várias ferramentas computacionais foram desenvolvidas para dar suporte nas várias etapas de concepção do artigo. As ferramentas existentes, que aplicam este tipo de suporte, são todas voltadas para outros temas de pesquisa, incompatíveis com os temas da Engenharia de Produção, que por sua vez possui maneiras particulares de redigir e estruturar o texto. O objetivo da pesquisa desenvolvida consistiu em adaptar e avaliar um instrumento de auxílio à escrita em inglês dirigido a pesquisadores da Engenharia de Produção, fundamentada na aprendizagem baseada em exemplos e em experiências. Para tal fim, foram adaptadas duas ferramentas existentes para auxiliar nas tarefas de leitura, anotação e redação de artigos científicos, avaliadas por meio de dois experimentos com dez alunos de pós-graduação em Engenharia de Produção em universidade pública, nas quais o resultado foi aferido por intermédio de um questionário, buscando identificar os efeitos da utilização sobre o aprendizado e o tempo demandado. O instrumento adaptado oferece, além de exemplos extraídos de artigos publicados, uma estrutura mais coerente com os artigos relacionados à Engenharia de Produção. Os resultados apontam para 90% de aceitação do novo instrumento, em que os alunos relataram um efeito positivo sobre suas habilidades de escrita de artigos, além de uma economia de 11% no tempo dedicado à escrita. Assim sendo, o instrumento tem potencial de auxílio à escrita e sua aplicação traz benefícios reais aos usuários, passíveis de serem adaptadas para qualquer outra área de pesquisa. / Scientific articles are the main communication means of disseminating results obtained by researchers around the world. However, writing scientific articles to highimpact journals is a complex task to authors for whom English is a second language. By means of example- and experience-based learning, reading, interpretation, and writing skills as regards the production of scientific texts can be developed through practice, facilitated by the use of reusable text snippets. Several computational tools have been developed to support the various phases of scientific writing in English. Existing tools that cater to this type of support are all geared to other research topics, incompatible with those inherent to Production Engineering, which has particular features of writing and structuring texts. The purpose of this research was to adapt and assess a new tool to help Production Engineering researchers to write articles English, grounded on example- and experience-based learning. To this end, two existing tools that aid scientists to read, annotate, and write articles in English were adapted and assessed through two experiments with ten Production Engineering graduate students at Brazilian public universities. Data were collected through a questionnaire in order to identify the effect of these tools on participants learning and time required to write articles. The adapted tools provide, in addition to snippets from published articles on Production Engineering, a structure more consistent with this field of knowledge. Results indicate 90% satisfaction rate with the new tool. Also, participants reported a positive effect on their writing skills as well as an 11% reduction in their time spent on scientific writing. Therefore, the tools in question have shown great potential to assist Production Engineering researchers in writing articles; moreover, their features may be adapted to scientific writing in other fields of knowledge.

Cette thèse s'intéresse à un problème logique dont les enjeux théoriques et pratiques sont multiples. De manière simple, il peut être présenté ainsi : imaginez que vous êtes dans un labyrinthe, dont vous connaissez toutes les routes menant à chacune des portes de sortie. Derrière l'une de ces portes se trouve un trésor, mais vous n'avez le droit d'ouvrir qu'une seule porte. Un vieil homme habitant le labyrinthe connaît la bonne sortie et se propose alors de vous aider à l'identifier. Pour cela, il vous indiquera la direction à prendre à chaque intersection. Malheureusement, cet homme ne parle pas votre langue, et les mots qu'il utilise pour dire ``droite'' ou ``gauche'' vous sont inconnus. Est-il possible de trouver le trésor et de comprendre l'association entre les mots du vieil homme et leurs significations ? Ce problème, bien qu'en apparence abstrait, est relié à des problématiques concrètes dans le domaine de l'interaction homme-machine. Remplaçons le vieil homme par un utilisateur souhaitant guider un robot vers une sortie spécifique du labyrinthe. Ce robot ne sait pas en avance quelle est la bonne sortie mais il sait où se trouvent chacune des portes et comment s'y rendre. Imaginons maintenant que ce robot ne comprenne pas a priori le langage de l'humain; en effet, il est très difficile de construire un robot à même de comprendre parfaitement chaque langue, accent et préférence de chacun. Il faudra alors que le robot apprenne l'association entre les mots de l'utilisateur et leur sens, tout en réalisant la tâche que l'humain lui indique (i.e.trouver la bonne porte). Une autre façon de décrire ce problème est de parler d'auto-calibration. En effet, le résoudre reviendrait à créer des interfaces ne nécessitant pas de phase de calibration car la machine pourrait s'adapter,automatiquement et pendant l'interaction, à différentes personnes qui ne parlent pas la même langue ou qui n'utilisent pas les mêmes mots pour dire la même chose. Cela veut aussi dire qu'il serait facile de considérer d’autres modalités d'interaction (par exemple des gestes, des expressions faciales ou des ondes cérébrales). Dans cette thèse, nous présentons une solution à ce problème. Nous appliquons nos algorithmes à deux exemples typiques de l'interaction homme robot et de l'interaction cerveau machine: une tâche d'organisation d'une série d'objets selon les préférences de l'utilisateur qui guide le robot par la voix, et une tâche de déplacement sur une grille guidé par les signaux cérébraux de l'utilisateur. Ces dernières expériences ont été faites avec des utilisateurs réels. Nos résultats démontrent expérimentalement que notre approche est fonctionnelle et permet une utilisation pratique d’une interface sans calibration préalable. / This thesis investigates how a machine can be taught a new task from unlabeled humaninstructions, which is without knowing beforehand how to associate the human communicative signals withtheir meanings. The theoretical and empirical work presented in this thesis provides means to createcalibration free interactive systems, which allow humans to interact with machines, from scratch, using theirown preferred teaching signals. It therefore removes the need for an expert to tune the system for eachspecific user, which constitutes an important step towards flexible personalized teaching interfaces, a key forthe future of personal robotics.Our approach assumes the robot has access to a limited set of task hypotheses, which include the task theuser wants to solve. Our method consists of generating interpretation hypotheses of the teaching signalswith respect to each hypothetic task. By building a set of hypothetic interpretation, i.e. a set of signallabelpairs for each task, the task the user wants to solve is the one that explains better the history of interaction.We consider different scenarios, including a pick and place robotics experiment with speech as the modalityof interaction, and a navigation task in a brain computer interaction scenario. In these scenarios, a teacherinstructs a robot to perform a new task using initially unclassified signals, whose associated meaning can bea feedback (correct/incorrect) or a guidance (go left, right, up, ...). Our results show that a) it is possible tolearn the meaning of unlabeled and noisy teaching signals, as well as a new task at the same time, and b) itis possible to reuse the acquired knowledge about the teaching signals for learning new tasks faster. Wefurther introduce a planning strategy that exploits uncertainty from the task and the signals' meanings toallow more efficient learning sessions. We present a study where several real human subjects controlsuccessfully a virtual device using their brain and without relying on a calibration phase. Our system identifies, from scratch, the target intended by the user as well as the decoder of brain signals.Based on this work, but from another perspective, we introduce a new experimental setup to study howhumans behave in asymmetric collaborative tasks. In this setup, two humans have to collaborate to solve atask but the channels of communication they can use are constrained and force them to invent and agree ona shared interaction protocol in order to solve the task. These constraints allow analyzing how acommunication protocol is progressively established through the interplay and history of individual actions.