This paper considers the problem of conducting inference on the regression coefficient in a bivariate regression model with a highly persistent regressor. Gaussian power envelopes are obtained for a class of testing procedures satisfying a conditionality restriction. In addition, the paper proposes feasible testing procedures that attain these Gaussian power envelopes whether or not the innovations of the regression model are normally distributed.

It is well-known that size-adjustments based on Edgeworth expansions for the t-statistic perform poorly when instruments are weakly correlated with the endogenous explanatory variable. This paper shows, however, that the lack of Edgeworth expansions and bootstrap validity are not tied to the weak instrument framework, but instead depends on which test statistic is examined. In particular, Edgeworth expansions are valid for the score and conditional likelihood ratio approaches, even when the instruments are uncorrelated with the endogenous explanatory variable. Furthermore, there is a belief that the bootstrap method fails when instruments are weak, since it replaces parameters with inconsistent estimators. Contrary to this notion, we provide a theoretical proof that guarantees the validity of the bootstrap for the score test, as well as the validity of the conditional bootstrap for many conditional tests. Monte Carlo simulations show that the bootstrap actually decreases size distortions in both cases.

The Latin American economic development thought; The Brazilian agrarian question; The Brazilian pattterns of accumulation; The crisis of the agricultural export sector; Structural changes from 1930 to 1954; The process of capital accumulation since 1954; Final remarks.

O livro apresenta artigos de opinião reunidos em quatro grandes temáticas: Futebol e Opressões; Futebol e Neoliberalismo; Futebol e Política Nacional; Futebol e Outros Mundos Possíveis. Com uma escrita leve, busca-se interpretar e refletir sobre o que ocorre dentro e fora das quatro linhas à luz de conceitos de pensadores e pensadoras das Ciências Humanas. Texto de contracapa: A ideia do livro é servir como porta de entrada – ou pontapé inicial – para leitores e leitoras que queiram se familiarizar com aspectos das Ciências Humanas que possibilitem interpretar o fenômeno do futebol, podendo ser instrumento de divulgação científica. E, claro, isso a partir de uma visão crítica sobre a realidade social e sobre o que ocorre dentro e fora de campo.

This paper considers tests of the parameter of an endogenous variable in an instrumental variables regression model. The focus is on one-sided conditional t-tests. Theoretical and numerical work shows that the conditional 2SLS and Fuller t-tests perform well even when instruments are weakly correlated with the endogenous variable. When the population F-statistic is as small as two, their power is reasonably close to the power envelopes for similar and non-similar tests which are invariant to rotation transformations of the instruments. This finding is surprising considering the bad performance of two-sided conditional t-tests found in Andrews, Moreira, and Stock (2007). We show these tests have bad power because the conditional null distributions of t-statistics are asymmetric when instruments are weak. Taking this asymmetry into account, we propose two-sided tests based on t-statistics. These novel tests are approximately unbiased and can perform as well as the conditional likelihood ratio (CLR) test.