Comparing two multivariate unit root tests

In this essay, a method for comparing the asymptotic power of the multivariate unit root tests proposed in Phillips & Durlauf (1986) and Flˆores, Preumont & Szafarz (1996) is proposed. In order to determine the asymptotic power of the tests the asymptotic distributions under the null hypothesis and under the set of alternative hypotheses described in Phillips (1988) are determined. In addition, a test which combines characteristics of both tests is proposed and its distributions under the null hypothesis and the same set of alternative hypotheses are determined. This allows us to determine what causes any difference in the asymptotic power of the two tests against the set of alternative hypotheses considered

Purchasing power parity and the unit root tests: a robust analysis

Empirical evidence suggests that real exchange rate is characterized by the presence of near-unity and additive outliers. Recent studeis have found evidence on favor PPP reversion by using the quasi-differencing (Elliott et al., 1996) unit root tests (ERS), which is more efficient against local alternatives but is still based on least squares estimation. Unit root tests basead on least saquares method usually tend to bias inference towards stationarity when additive out liers are present. In this paper, we incorporate quasi-differencing into M-estimation to construct a unit root test that is robust not only against near-unity root but also against nonGaussian behavior provoked by assitive outliers. We re-visit the PPP hypothesis and found less evidemce in favor PPP reversion when non-Gaussian behavior in real exchange rates is taken into account.

Testing unit root based on partially adaptive estimation

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.

A PPCCIPS: a Política Pública da Coleta Complementar Itinerante e Programada de Sangue, sob a luz da teoria do ciclo da política pública

This study aimed to focus on aspects of public administration concerning the implementation of the public policy of complementary blood collection by the itinerant and scheduled PPCCIPS services either trough off local unity or mobile unit blood collection operations, which are managed by the State Institute of Hematology Arthur de Siqueira Cavalcanti - HEMORIO. The case study method was used in that public health institutional field, in search for a better understanding of responsibilities and management related to collection, serology, fractionation, storage and distribution of blood supply to almost all public hospitals and clinics, summed up to agreements with the single health system of the State of Rio de Janeiro. Bibliographic references, documentary and field data obtained through interviews and systematic observation in the public servants of HEMORIO workplaces, were treated by the analysis of the content method and the results of this research revealed the complexity of those services, and needs in outstanding aspects of infrastructure, equipment, logistics and personnel, which are critical for the achievement of the increased public collection of blood in the Rio de Janeiro State, endorsing the suggestions for the implementation of PPCCIPS in HEMORIO. The main point found in this research results concern the immanent ethical commitment of that public service personnel, including staff members and low ranking members as well, perceived due to a brief philosophical overlook on that personnel¿s attitudes. An important strategic aspect was revealed by the need for excellence of midia communications and education programs to implement the community involvement in the whole process. Final reflections point out that personnel posture is considered vital for the quality of the expected care of the technical activities and also for the quality of its final products release to the local public, fluminense, which is the irreplaceable human blood, and their derivatives. Despite the author¿s effort in this dissertation there is much more to be studied on that crucial theme.

Learning-by-employing: the value of commitment

We analyze a dynamic principal–agent model where an infinitely-lived principal faces a sequence of finitely-lived agents who differ in their ability to produce output. The ability of an agent is initially unknown to both him and the principal. An agent’s effort affects the information on ability that is conveyed by performance. We characterize the equilibrium contracts and show that they display short–term commitment to employment when the impact of effort on output is persistent but delayed. By providing insurance against early termination, commitment encourages agents to exert effort, and thus improves on the principal’s ability to identify their talent. We argue that this helps explain the use of probationary appointments in environments in which there exists uncertainty about individual ability.

From commitment to non-commitment: allowing type dynamic in Laffont and Tirole's regulation model

This paper investigates the introduction of type dynamic in the La ont and Tirole's regulation model. The regulator and the rm are engaged in a two period relationship governed by short-term contracts, where, the regulator observes cost but cannot distinguish how much of the cost is due to e ort on cost reduction or e ciency of rm's technology, named type. There is asymmetric information about the rm's type. Our model is developed in a framework in which the regulator learns with rm's choice in the rst period and uses that information to design the best second period incentive scheme. The regulator is aware of the possibility of changes in types and takes that into account. We show how type dynamic builds a bridge between com- mitment and non-commitment situations. In particular, the possibility of changing types mitigates the \ratchet e ect". We show that for small degree of type dynamic the equilibrium shows separation and the welfare achived is close to his upper bound (given by the commitment allocation).

As relações entre liderança, cultura organizacional e clima organizacional da criminalística da Polícia Federal

As organizações estão conscientes que enfrentarão complexa mudança organizacional, pois as demandas individuais na participação das decisões têm alterado os papéis desempenhados pelos gestores e seus subordinados. Neste contexto, a comunicação torna-se essencial para o exercício da influência social, para a coordenação das atividades e para a efetivação da liderança. A literatura aponta que as atitudes e os comportamentos dos funcionários são regidos por uma distribuição justa das recompensas conforme às contribuições de cada um. Assim, satisfação e atitudes positivas podem ser alcançadas por meio de um ambiente organizacional com boa comunicação, autonomia, participação, justiça distributiva e confiança. Portanto, este trabalho teve o objetivo de identificar as dimensões de Liderança e Cultura Organizacional na Criminalística da Polícia Federal, suas relações com o Clima Organizacional e como estes construtos contribuem para explicação dos problemas gerenciais. Para a coleta dos dados, foi realizada uma pesquisa quantitativa composta de 4 questionários. Dos 722 formulários enviados, 150 (20,8 %) foram respondidos: 21 (14 %) por Peritos Criminais Federais (PCF) do órgão central, 126 (84 %) por PCF das descentralizadas e 3 (2 %) por PCF de outras unidades. Os entrevistados tinham de 30 a 64 anos de idade (μ = 40,9; dp = 6,8), de 1 a 32 anos de serviço público (μ = 12,6; dp = 6,5) e de 1 a 27 anos de nomeação (μ = 7,9; dp = 3,9), e a função de chefia foi exercida por 79 (52,7 %) respondentes. Os resultados revelaram que não há diferença nas percepções de Liderança, Cultura e Clima Organizacional entre as regiões do país, rejeitando a hipótese H6 deste trabalho. Em um estudo longitudinal entre 2011 e 2013 também não houve mudanças significativas na percepção de Liderança, mostrando consistência entre as populações. Além disso, os resultados mostraram que a idade, o tempo de trabalho e o tempo de nomeação não estão associados com o Clima, logo servidores de diferentes épocas têm a mesma percepção do clima da organização. Os modelos de equações estruturais demonstraram que a Liderança, as Práticas de Liderança e o Clima são explicados fortemente por suas dimensões, e que a Cultura Organizacional afeta a Liderança e as Práticas de Liderança porém, mais significativamente, o Clima Organizacional. Tais resultados corroboram a teoria e explicam hipóteses deste trabalho. Observou-se, também, que na organização há predomínio da subcultura burocrática, baseada em controle e poder, que impacta o Clima Organizacional e, frequentemente, resulta em menor comprometimento e desempenho do servidor. A pesquisa apontou que os líderes devem encorajar a comunicação aberta para alcançar o entendimento dialógico na organização. Os achados deste estudo podem fornecer à gestão uma visão melhor para gerir seus recursos com base na legitimidade, na referência, no conhecimento e na informação, obedecendo os pressupostos do discurso ideal habermasiano.

Creating buyer-supplier commitment in food supply chains at the base of the pyramid

Esta pesquisa analisa o papel dos aspectos relacionais tais como confiança, comprometimento, interdependência e uso de poder âmbito das estratégias de negócios inclusivos que envolvem pequenos agricultores nas cadeias de valor de multinacionais dos agronegócios no Brasil. Os negócios inclusivos de abastecimento direto por empresas com pequenos agricultores em países em desenvolvimento têm sido reconhecidos como uma abordagem economicamente viavél e promissora para criar impacto social e melhorar as condições de vida de produtores rurais da "base da pirâmide", ao mesmo tempo permitindo que as empresas reforçar as suas posições nos mercados locais e adquirir matérias primas de qualidade a custos mais baixos. Estudos sobre este tema focam amplamente sobre as vantagens comerciais e competitivas que as empresas derivam do abastecimento direito com pequenos fornecedores, apresentando modelos de cadeia de valor customizados e ajustados estratégias globais de negócios, no entanto ainda há pouco conhecimento teoricamente fundamentado sobre os desafios organizacionais e relacionais da relação entre o comprador multinacional e o fornecedor de baixa renda. Além disso, pouco foco tem-se prestado sobre como assimetrias entre multinacionais e produtores de baixa renda, em questão de poder, dependência e de valores pode afetar a evolução dessas relações de negócios. O objetivo do estudo foi descrever os fatores que permitem a esses parceiros assimétricos de construir relacionamentos comerciais de longo prazo e mutuamente benéficos. A metodologia da teoria fundamentada foi usada e foi particularmente adequada para examinar as relações entre comprador e fornecedor e para recolher experiências de campo em três setores principais dominados pela agricultura familiar no Brasil, ou seja laticínios, avi-suinocultura e produção hortícola. Os principais conceitos teóricos da área de Relationship Marketing foram usados para apoiar os resultados da pesquisa de campo. A principal conclusão desta pesquisa é a importância de ir além da construção de confiança na estratégia de gestão do relacionamento entre comprador e fornecedor e de criar parcerias diádicas baseadas na interdependência mútua, a fim de reduzir as assimetrias e melhorar o comprometimento entre a empresa e o pequeno agricultor.

Multivariate unit root tests

A new multivariate test for the detection ofunit roots is proposed. Use is made ofthe possible correlations between the disturbances of difIerent series, and constrained and unconstrained SURE estimators are employed. The corresponding asymptotic distributions, for the case oftwo series, are obtained and a table with criticai vaIues is generated. Some simulations indivate that the procedure performs better than the existing alternatives.

Unit roots and the welfare gains of cycle smoothing

li consumption is log-Normal and is decomposed into a linear deterministic trend and a stationary cycle, a surprising result in business-cycle research is that the welfare gains of eliminating uncertainty are relatively small. A possible problem with such calculations is the dichotomy between the trend and the cyclical components of consumption. In this paper, we abandon this dichotomy in two ways. First, we decompose consumption into a deterministic trend, a stochastic trend, and a stationary cyclical component, calculating the welfare gains of cycle smoothing. Calculations are carried forward only after a careful discussion of the limitations of macroeconomic policy. Second, still under the stochastic-trend model, we incorporate a variable slope for consumption depending negatively on the overall volatility in the economy. Results are obtained for a variety of preference parameterizations, parameter values, and different macroeconomic-policy goals. They show that, once the dichotomy in the decomposition in consumption is abandoned, the welfare gains of cycle smoothing may be substantial, especially due to the volatility effect.

A unit root test based on partially adaptive estimation

This paper constructs a unit root test baseei on partially adaptive estimation, which is shown to be robust against non-Gaussian innovations. We show that the limiting distribution of the t-statistic is a convex combination of standard normal and DF distribution. Convergence to the DF distribution is obtaineel when the innovations are Gaussian, implying that the traditional ADF test is a special case of the proposed testo Monte Carlo Experiments indicate that, if innovation has heavy tail distribution or are contaminated by outliers, then the proposed test is more powerful than the traditional ADF testo Nominal interest rates (different maturities) are shown to be stationary according to the robust test but not stationary according to the nonrobust ADF testo This result seems to suggest that the failure of rejecting the null of unit root in nominal interest rate may be due to the use of estimation and hypothesis testing procedures that do not consider the absence of Gaussianity in the data.Our results validate practical restrictions on the behavior of the nominal interest rate imposed by CCAPM, optimal monetary policy and option pricing models.

Market clearing sealed-bid auctions for non-identical objects with single-unit demands

We consider a version of the cooperative buyer-seller market game of Shapley and Shubik (1972). For this market we propose a c1ass of sealed- bid auctions where objects are sold simultaneously at a market c1earing price rule. We ana1yze the strategic games induced by these mechanisms under the complete information approach. We show that these noncooperative games can be regarded as a competitive process for achieving a cooperative outcome: every Nash equilibrium payoff is a core outcome of the cooperative market game. Precise answers can be given to the strategic questions raised.