Minimum disparity estimation based on combined disparities: Asymptotic results

The maximum likelihood estimator (MLE) is asymptotically efficient for most parametric models under standard regularity conditions, but it has very poor robustness properties. On the other hand some of the minimum disparity estimators like the minimum Hellinger distance estimator (MHDE) have strong robustness features but their small sample efficiency at the model turns out to be very poor compared to the MLE. Methods based on the minimization of some combined disparities can substantially improve their small sample performances without affecting their robustness properties (Park et al., 1995). All studies involving the combined disparity have so far been empirical, and there are no results on the asymptotic properties of these estimators. In view of the usefulness of these procedures this is a major gap in theory, which we try to fill through the present work. Some illustrations of the performance of the estimators and the corresponding tests are also provided.     

An investigation of Kendall's τ modified for censored data with applications

To accommodate testing for independence in bivariate data subject to censoring, several modifications of Kendall's τ are discussed. An extensive computer simulation is done to investigate power properties of these modifications under alternatives of the bivariate normal or bivariate exponential types. The statistics are then applied to available heart pacemaker patient survival data.     

Likelihood Ratio Testing for Hidden Markov Models Under Non-standard Conditions

Abstract.  In practical applications, when testing parametric restrictions for hidden Markov models (HMMs), one frequently encounters non-standard situations such as testing for zero entries in the transition matrix, one-sided tests for the parameters of the transition matrix or for the components of the stationary distribution of the underlying Markov chain, or testing boundary restrictions on the parameters of the state-dependent distributions. In this paper, we briefly discuss how the relevant asymptotic distribution theory for the likelihood ratio test (LRT) when the true parameter is on the boundary extends from the independent and identically distributed situation to HMMs. Then we concentrate on discussing a number of relevant examples. The finite-sample performance of the LRT in such situations is investigated in a simulation study. An application to series of epileptic seizure counts concludes the paper.     

Spatial variation in contraceptive use in Bangladesh: Looking Beyond the borders

This article promotes a more complete understanding of social change by analyzing spatial patterns of contraceptive use in Bangladesh and the contiguous state of West Bengal in India. Multilevel analyses that control for variations in individual- and household-level correlates show an important role for cross-border influences only in those districts that share a common language across the border. The districts that are positive outliers in contraception hug the Bangladesh-West Bengal border. A map of outliers shows that the positive outliers form a contiguous band in a manner suggestive of a role for contagion.     

The determinants of union membership growth in Taiwan

This paper examines the determinants of intertemporal variation in the growth rate of trade union membership in Taiwan during 1960–1987. The empirical results indicate that the widely used empirical model of growth in trade union membership based largely on cyclical variables applies to the case of a newly industrialized Asian country—Taiwan.     

THE IMPACT OF CLASSROOM EXPERIMENTS ON THE LEARNING OF ECONOMICS: AN EMPIRICAL INVESTIGATION

This paper provides limited evidence on the effectiveness of a simple classroom experiment. In different courses in environmental economics or public finance, a brief take-some game was performed. Students who took part in this classroom experiment, as well as those who just watched it, were more successful in answering a multiple-choice test on the "tragedy of the commons" than control groups from the same courses.     

TESTING FOR INDEPEDENCE IN MULTIVARIATE EXPONENTIAL DISTRIBUTIONS2

In this paper the work of Weier & Basu (1980) is extended to a special case of the trivariate exponential distributions and to the general k-variate case. In the trivariate case several statistics are derived including one based on the likelihood ratio approach and the locally most powerful rank statistic, and power studies are carried out. The general k-variate model is derived, and testing for independence is shown to reduce to a solved problem.