829 resultados para Social hypothesis testing
Resumo:
Many key economic and financial series are bounded either by construction or through policy controls. Conventional unit root tests are potentially unreliable in the presence of bounds, since they tend to over-reject the null hypothesis of a unit root, even asymptotically. So far, very little work has been undertaken to develop unit root tests which can be applied to bounded time series. In this paper we address this gap in the literature by proposing unit root tests which are valid in the presence of bounds. We present new augmented Dickey–Fuller type tests as well as new versions of the modified ‘M’ tests developed by Ng and Perron [Ng, S., Perron, P., 2001. LAG length selection and the construction of unit root tests with good size and power. Econometrica 69, 1519–1554] and demonstrate how these tests, combined with a simulation-based method to retrieve the relevant critical values, make it possible to control size asymptotically. A Monte Carlo study suggests that the proposed tests perform well in finite samples. Moreover, the tests outperform the Phillips–Perron type tests originally proposed in Cavaliere [Cavaliere, G., 2005. Limited time series with a unit root. Econometric Theory 21, 907–945]. An illustrative application to U.S. interest rate data is provided
Resumo:
Stable isotope ratios (δ13C and δ15N) were measured in human burials from the post-medieval (16th–18th c. AD) Carmelite friary burial grounds at Aalst, a town in Flanders, Belgium. Dietary patterns of 39 adult individuals were analyzed, from a mixed monastic and lay population buried in three different locations, reflecting groups with differing social status. The data show significant variation in the consumption of perhaps meat, but certainly also marine protein between females and males. This result represents a remarkable continuity with medieval dietary patterns, suggesting that the social and economic changes of the early modern period had a limited effect on everyday life. When both sexes were examined together, individuals buried in the cloister garth consumed significantly less marine protein compared to people buried in the church, likely reflecting social stratification. No statistical differences were observed between isotopic values from the church and the cloister alley, suggesting a similarly diverse diet of the monastic part of the buried population and that of the richer lay population. Finally, the hypothesis that diffuse idiopathic skeletal hyperostosis (DISH) is linked to a diet rich in animal protein was tested. No systematic or statistically significant differences between pathological and non-pathological bones from the same individuals affected with DISH were observed, and no statistical differences were found between individuals with DISH and individuals without DISH
Resumo:
Two competing hypotheses have been suggested to explain thermal sensitivity of lizards to environmental conditions. These are the static and the labile hypotheses. The static hypothesis posits that thermal physiology is evolutionary conservative and consequently relatively insensitive to directional selection. Contrarily, the labile hypothesis states that thermal physiology does respond readily to directional selection in some lizard taxa. In this paper, we tested both hypotheses among species of Liolaemus lizards. The genus Liolaemus is diverse with about 200 species, being broadly distributed from central Peru to Tierra del Fuego at the southern end of South America. Data of field body temperature (T(b)) from Liolaemus species were collected from the literature. Based on the distributional range of the species we also collected data of mean annual ambient temperatures. We observed that both the traditional analysis and the phylogenetic approach indicate that in the genus Liolaemus T(b) of species varies in a manner that is consistent with ecological gradient of ambient temperature. The data suggest that the thermal physiology of Liolaemus lizards is evolutionarily flexible, and that this plasticity has been partially responsible for the colonization of a wide array of thermal environments. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
A modified version of the social habituation/dis-habituation paradigm was employed to examine social recognition memory in Wistar rats during two opposing (active and inactive) circadian phases, using different intertrial intervals (30 and 60 min). Wheel-running activity was monitored continuously to identify circadian phase. To avoid possible masking effects of the light-dark cycle, the rats were synchronized to a skeleton photoperiod, which allowed testing during different circadian phases under identical lighting conditions. In each trial, an infantile intruder was introduced into an adult`s home-cage for a 5-minute interaction session, and social behaviors were registered. Rats were exposed to 5 trials per day for 4 consecutive days: oil days I and 2, each resident was exposed to the same intruder; on days 3 and 4, each resident was exposed to a different intruder in each trial. I he resident`s social investigatory behavior was more intense when different intruders were presented compared to repeated presentation of the same intruder, suggesting social recognition memory. This effect was stronger when the rats were tested during the inactive phase and when the intertrial interval was 60 min, These findings Suggest that social recognition memory, as evaluated in this modified habituation/dis-habituation paradigm, is influenced by the circadian rhythm phase during which testing is performed, and by intertrial interval. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
This paper proposes unit tests based on partially adaptive estimation. The proposed tests provide an intermediate class of inference procedures that are more efficient than the traditional OLS-based methods and simpler than unit root tests based on fully adptive estimation using nonparametric methods. The limiting distribution of the proposed test is a combination of standard normal and the traditional Dickey-Fuller (DF) distribution, including the traditional ADF test as a special case when using Gaussian density. Taking into a account the well documented characteristic of heavy-tail behavior in economic and financial data, we consider unit root tests coupled with a class of partially adaptive M-estimators based on the student-t distributions, wich includes te normal distribution as a limiting case. Monte Carlo Experiments indicate that, in the presence of heavy tail distributions or innovations that are contaminated by outliers, the proposed test is more powerful than the traditional ADF test. We apply the proposed test to several macroeconomic time series that have heavy-tailed distributions. The unit root hypothesis is rejected in U.S. real GNP, supporting the literature of transitory shocks in output. However, evidence against unit roots is not found in real exchange rate and nominal interest rate even haevy-tail is taken into a account.
Resumo:
In this paper, we show that the widely used stationarity tests such as the KPSS test have power close to size in the presence of time-varying unconditional variance. We propose a new test as a complement of the existing tests. Monte Carlo experiments show that the proposed test possesses the following characteristics: (i) In the presence of unit root or a structural change in the mean, the proposed test is as powerful as the KPSS and other tests; (ii) In the presence a changing variance, the traditional tests perform badly whereas the proposed test has high power comparing to the existing tests; (iii) The proposed test has the same size as traditional stationarity tests under the null hypothesis of stationarity. An application to daily observations of return on US Dollar/Euro exchange rate reveals the existence of instability in the unconditional variance when the entire sample is considered, but stability is found in subsamples.
Resumo:
Esta dissertação apresenta uma análise da proposição de ações de responsabilidade social empresarial em micro e pequenas empresas, a partir de uma orientação da governança de um Arranjo Produtivo Local. A atualidade do tema o aproxima do desenvolvimento sustentável, entendido como alternativa de inserção econômica e social num ambiente em que predominou a globalização de mercados sob orientação neoliberal. Para a pesquisa de campo foi escolhido o arranjo de moda íntima de Nova Friburgo e região, no Rio de Janeiro. O elevado grau de informalidade que ainda existe em empresas de confecção, bem como a quantidade de resíduos que geram, reforçam o interesse em se conhecer o escopo e o alcance das práticas de responsabilidade social. A hipótese é de que as ações existentes não estão consistentemente consolidadas na orientação da governança, nem se constituem em caminhos decisivos para um desenvolvimento sustentável.
Resumo:
In the last decades of the 21st century, Corporate Social Responsibility (CSR) has become one of the most widely debated issues in business management, concerning researchers, politicians, managers and society at large. With multilateral implications in economic and social life, CSR refers, essentially, to the discussion about the boundaries of business intervention in society and the ethical limits that should regulate that intervention. It questions the impact of business practices in social well-being, the role left for corporations and for the State in attending to community needs, and which are, at last, the responsibilities that tie enterprises to society. In this research, CSR is approached from the perspective of its ethical foundations, based on the moral reasoning of the business manager, as a key organizational leader with relevant decision power. Specifically, the research aims to understand how the personal human value system and the ethical orientation of managers influence their attitude towards CSR, considering this attitude as an indicator of managerial behavior that translates into corporate performance. Theoretically, CSR concept is discussed and presented as a set of social commitments, based on a strict interpretation of its meaning. As to human values, its philosophical roots are briefly analyzed and Schwartz modern motivational theory is addressed as main reference for studying the personal value system of managers in this research. Concerning ethics, based on classical theory from moral philosophy, references are seek in John Stuart Mill¿s utilitarianism, Immanuel Kant¿s deontological absolutism, John Rawls¿s theory of justice and the ethics of virtue inspired by Aristotle¿s moral thoughts. Based on an extended literature review, research hypothesis are proposed as part of a theoretical model of analysis named Individual Attitude Towards Social Responsibility Model. In order to test the theory¿s empirical validity, it was conducted a field study with 252 Brazilian managers, mainly from the metropolitan areas of São Paulo and Rio de Janeiro. Results show that managerial attitude aligned with CSR principles is favored by conservative personal values, protectors of stability and centered on collective will, and by an ethical orientation based on egalitarianism as postulated by distributive justice principles. However, results also show that the influence of values and personal ethics on managerial attitude towards CSR only occur in managers younger than 30 years old. Findings and their meanings are discussed, as well as summarized in the Axiological and Ethical Determinants of Managers¿ Social Commitment Model. Finally, methodological limitations are evaluated and clues for further research are suggested.
Resumo:
The present work aims to identify emerging organizational changes in the Court of Accounts of the State of Rio de Janeiro - TCE/RJ that are happening in the contemporary scenery known as the Age of Information. The search for the comprehension of the institutional dynamics is oriented by concepts originated from the theory of complexity, which believe that the public services external control system can be understood in a political, technical and legal environment with growing levels of learning and innovation. While chasing the possible causes of these changes, we try to prove the hypothesis that the TCE/RJ is turning into a more transparent organization. For this purpose, we define the outlines and reaches of the principle of transparency, based in bibliographical and documental researches, and analyze the phenomenon perceived in a explanation research through semi-structured interviews performed with two groups: a sample representing the universe under jurisdiction entities top level directors and the other obtained in the universe of formal and informal leaderships existing in the educational body of the institution. The conclusion of the present work confirms the initial questions, indicating that the organization is really becoming more and more transparent. The social-technical changes that are happening today at the TCE/RJ are caused by the growing social pressure for more effective results in the control of public expenditures. Under the systemic point of view, we observe cracks in the protective bell-glass that evolves the institution - previously hermetic to the external contingencies and that works today as a SAC - Adaptive Complex System. Aspects such as organization structural changes, the introduction of strategic planning and the growing democratization of the decision process are producing a new organizational culture. The seniority of the Technical Headcount contributes to establish the pre-conditions for the development of a administration where the participation of the TCE/RJ technical employees adds importance to its development as an institution that generates republican effects in the society from its less hermetic decision process.
Resumo:
o objetivo deste trabalho é conhecer as possibilidades da Educação Libertária na prática de Responsabilidade Social, trabalhando a hipótese de que, através da educação libertadora e emancipatória dos excluídos sociais, esta prática alcança sustentabilidade, sem recorrer a assistencialismos tão comuns no discurso e ação de empresas, governo e indivíduos. Ao longo do trabalho, mais especificamente no estudo de caso, poderemos concluir que existem ações de responsabilidade social voltadas para uma mudança nas relações sociais, onde o discurso é substituído pela práxis na criação de oportunidades através da educação e compartilhamento do conhecimento. Na introdução do trabalho o leitor encontrará a contextualização do tema e a formulação do problema, bem como os objetivos do trabalho, a relevância do estudo e a delimitação do estudo. Na segunda parte, no referencial teórico, serão analisadas as principais publicações sobre educação libertária, estudadas à luz de seus principais pensadores e representantes. A ênfase será no autor Paulo Freire, representante da Pedagogia do Oprimido, de quem podemos aprender bastante sobre ação e reflexão. A terceira parte do trabalho fala sobre a metodologia exploratória utilizada na pesquisa, delimitada por um estudo de caso na disciplina Gestão Social, oferecida aos alunos de mestrado da Fundação Getúlio Vargas. Na quarta parte, será descrito o estudo de caso, sendo apresentadas as características da metodologia dialogal empregada na disciplina e das possibilidades da educação libertária na prática da responsabilidade social. Na quinta parte serão analisados os dados coletados no estudo de caso e apresentadas as conclusões constatadas. Nesta parte serão também confrontadas as diferenças de possibilidades entre educação tradicional e educação emancipatória.
Resumo:
O estudo busca investigar a atuação das grandes empresas varejista brasileiras com relação à Responsabilidade Social Empresarial (RSE), procurando levantar o estágio em que estas se encontram, e se são aproveitadas as características do varejo de capilaridade geográfica, contato direto com a comunidade, forte vinculo com os clientes, interação entre funcionários e clientes e proximidade física de Organizações Não Governamentais e instituições públicas. Para tanto, foram utilizados conceitos relacionados à gestão, como comprometimento da cúpula, incorporação de valores de RSE na administração e no planejamento estratégico, autonomia e gestão de RSE nas lojas. A gestão foi avaliada pela ótica do contínuo de colaboração de Austin, e as práticas de RSE por meio da teoria dos stakeholders (públicos interessados), utilizando como base as dimensões dos Indicadores Ethos de Responsabilidade Social. A teoria de Kotler e Lee, para a classificação das iniciativas conforme os conceitos do marketing, também foi empregada. Conduziu-se uma pesquisa exploratória com cinco grandes empresas do setor varejista. Os resultados encontrados apontam que na maioria das empresas a incorporação dessas práticas é recente. Constata-se que as empresas diferem quanto ao estágio de RSE e que as características próprias do varejo não são aproveitadas em sua totalidade. Hipóteses são levantadas para que estas aproveitem a estrutura das lojas para atender às necessidades da comunidade local.
Resumo:
o presente trabalho teve por objetivo investigar o relacionamento entre locus externo de causalidade e aquiescência de detentores de poder e a so1icitações de subordinados. Pesquisas anteriores realizadas nos Estado Unidos demonstraram das condições que afetam os indivíduos em situação de poder levando-os a atender as solicitações de dependentes. Esse estudo constitui uma réplica parcial do experimento de Schopler e Mathew B (1965) para o teste da mesma hipótese - o detentor de poder que percebe a dependência de seu parceiro motivada por fatores externos dar-lhe-á mais ajuda que quando percebe a dependência do parceiro motivada por auto escolha (fatores internos) - com sujeitos brasileiros. O mesmo “design” serviu para o teste de duas hipóteses adicionais: a) o detentor de poder ajuda mais sem parceiro dependente quando o custo da ajuda é baixo (hipótese de Thibaut e Kelly, 1967); b) o detentor de poder ajuda menos o parceiro, percebido como dependente por força de circunstâncias externas, quando conhece antecipadamente qual a sua solicitação (hipótese original deste trabalho). Os resultados confirmaram as hipóteses ao nível de 0,05. A discussão dos resultados obtidos foi desenvolvida em termos das teorias da troca e da reatância. Com base nos resu1tados conclui-se que: (1) as relações de poder não parecem ser influenciadas pela cultura em que os agentes estão inseridos; (2) a oposição à liberdade perdida pode explicar o menor atendimento a solicitações pré-conhecidas.
Resumo:
Este trabalho teve por objetivo o estudo de variáveis que convergem para o desenvolvimento da personalidade infantil. A conduta da mulher, em seu posicionamento frente a família e a sociedade, interferindo diretamente sobre a criança, e considerada primordial para análise do problema. O referencial teórico utilizado e social, sendo discutido dentro do contexto da psicologia feminina e de sua situação sócio-jurídica; das relações de estrutura e dinâmica familiares; da psicologia do desenvolvimento; e de fatores culturais envolvidos. Tratando-se de um estudo teórico, não são discutidas as proposições em nível de constructo nem de hipóteses. Limita-se ao nível das variáveis, buscando deduções lógicas que liguem a conscientização feminina das necessidades requeridas por seus diversos papeis com sua conduta.
Resumo:
In this paper, we show that the widely used stationarity tests such as the KPSS test has power close to size in the presence of time-varying unconditional variance. We propose a new test as a complement of the existing tests. Monte Carlo experiments show that the proposed test possesses the following characteristics: (i) In the presence of unit root or a structural change in the mean, the proposed test is as powerful as the KPSS and other tests; (ii) In the presence a changing variance, the traditional tests perform badly whereas the proposed test has high power comparing to the existing tests; (iii) The proposed test has the same size as traditional stationarity tests under the null hypothesis of covariance stationarity. An application to daily observations of return on US Dollar/Euro exchange rate reveals the existence of instability in the unconditional variance when the entire sample is considered, but stability is found in sub-samples.
Resumo:
Government transfers to individuals and families play a central role in the Brazilian social protection system, accounting for almost 14 per cent of GDP in 2009. While their fiscal and redistributive impacts have been widely studied, the macroeconomic effects of transfers are harder to ascertain. We constructed a Social Accounting Matrix (SAM) for 2009 and estimated short-term multipliers for seven different government monetary transfers . The SAM is a double-entry square matrix depicting all income flows in the economy. The data were compiled from the 2009 Brazilian National Accounts and the 2008/2009 POF, a household budget survey. Our SAM was disaggregated into 56 sectors, 110 commodities, 200 household groups and seven factors of production (capital plus six types of labor, according to schooling). Finally, we ran a set of regressions to separate household consumption into ‘autonomous’ (or ‘exogenous’) and ‘endogenous’ components. More specifically, we are interested in the effects of an exogenous injection into each of the seven government transfers outlined above. All the other accounts are thus endogenous. The so-called demand ‘leaks’ are income flows from the endogenous to exogenous accounts. Leaks—such as savings, taxes and imports—are crucial to determine the multiplier effect of an exogenous injection, as they allow the system to go back to equilibrium. The model assumes that supply is perfectly elastic to demand shocks. It assumes that the families’ propensity to save and consumption profile are fixed—that is, rising incomes do not provoke changes in behaviour. The multiplier effects of the on GDP corresponds to the growth in GDP resulting from each additional dollar injected into each transfer seven government transfers. If the government increased Bolsa Família expenditures by 1 per cent of GDP, overall economic activity would grow by 1.78 per cent, the highest effect. The Continuous Cash Benefit, comes second. Only three transfers— the private-sector and public servants’ pensions and FGTS withdrawals—had multipliers lower than unity. The multipliers for other relevant macroeconomic aggregates—household and total consumption, disposable income etc. —reveal a similar pattern. Thus, under the stringent assumptions of our model, we cannot reject the hypothesis that government transfers targeting poor households, such as the Bolsa Família, help foster economic expansion. Naturally, it should be stressed that the multipliers relate marginal injections into government transfers to short-term economic performance either real growth, or inflation if there is no idle capacity which is also useful to analyze. In the long term, there is no doubt that what truly matters is the growth of the country’s productive capacity.