A note on the projection properties of Hadamard matrices obtained by the first Payley construction

We show that the projections on four factors of an arbitrary orthogonal array of strength 2 allow the estimation of main effects and two-factor interactions when all other effects are assumed to be zero, if those projections satisfy the bounds given by Weils theorem. The only exceptions are the Hadamard matrices of orders 16 and 24. A consequence is again the estimability of main effects and two-factor interactions for the projections on four factors of the first Payley construction for arbitrary run size.     

如何面对公司的增长要求

公司必须增长,但是以错误的方法寻求增长比不增长更糟糕     

Three Corrected Score Tests for Generalized Linear Models with Dispersion Covariates

We develop three corrected score tests for generalized linear models with dispersion covariates, thus generalizing the results of Cordeiro , Ferrari and Paula (1993) and Cribari-Neto and Ferrari (1995) . We present, in matrix notation, general formulae for the coefficients which define the corrected statistics. The formulae only require simple operations on matrices and can be used to obtain analytically closed-form corrections for score test statistics in a variety of special generalized linear models with dispersion covariates. They also have advantages for numerical purposes since our formulae are readily computable using a language supporting numerical linear algebra. Two examples, namely, iid sampling without covariates on the mean or dispersion parameter oand one-way classification models, are given. We also present some simulations where the three corrected tests perform better than the usual score test, the likelihood ratio test and its Bartlett corrected version. Finally, we present a numerical example for a data set discussed by Simonoff and Tsai (1994) .     

Differences in exchange rate pass-through in the euro area

This paper focuses on the pass-through of exchange rate changes into the prices of imports made by euro area countries originating outside the area. Using data on import unit values for 13 different product categories for each country, we estimate industry-specific rates of pass-through across and within countries for all euro members. In the short-run, pass-through rates differ across industries and countries and are less than one. In the long-run neither full pass-through nor equality of pass-through rates across industries and countries can be rejected. Differences exist across euro area countries in the degree that a common exchange rate movement gets transmitted into consumer prices and costs of production indices. Most of these differences in transmission rates are due to the distinct degree of openness of each country to non-euro area imports rather than to the heterogeneity in the structure of imports.     

Revealed preference and differentiable demand

Summary. We prove that, for finitely many demand observations, the Strong Axiom of Revealed Preference tests not only the existence of a strictly concave, strictly monotone and continuous utility generator, but also one that generates an infinitely differentiable demand function. Our results extend those of previous related results (Matzkin and Richter, 1991; Chiappori and Rochet, 1987), yielding differentiable demand functions but without requiring differentiable utility functions.Received: 1 November 2001, Revised: 5 February 2004, JEL Classification Numbers: D11, D12. Correspondence to: Kam-Chau WongThis is a much revised version of Lee and Wong (2001). We are grateful to the Referee for valuable suggestions. We also thank Professor Marcel K. Richter for his comments.     

The interactions between natural and physical capitals in the tourist lifecycle model

This paper presents a model of the interactions between natural resources and physical capital in the evolution of a tourist destination. The projected trajectory of the number of tourists approaches the classical lifecycle pattern. The post-stagnation phase is analyzed within the model, obtaining different patterns which depend on the impacts of physical capital on both demand and environmental degradation. The magnitudes of these impacts are determined by the type of tourism. An empirical application to the case of the tourist industry in the Canary Islands (Spain) is presented, showing that the model can represent the general characteristics of the post-stagnation phase of a tourist destination.