Alan Dorfman

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Comoran coelacanths are sluggish, nocturnal drift hunters that feed on other fish and have a low metabolic rate. During the day, they retreat to the still water of deep lava caves. The Indonesian sites would therefore seem to be unsuitable for sustaining a viable population of L. chalumnae. So far, four Indonesian coelacanths have been found in a relatively(More)
We describe a test, based on the correlation integral, for the independence of a variable and a vector that can be used to detect model misspecification in serially dependent data. In Monte Carlo simulations this test performs nearly as well or better than the BDS test in univariate time series and complements the BDS test in distributed lag models.(More)
In the present work we explicate the application of maximum likelihood inference in the analysis of surveys which are the result of (possibly informative) stratified sampling. In Section 1 we review basic ideas, including two general results useful for applying maximum likelihood to sample data. Ideas are illustrated by a simple through the origin(More)
Stratification is one of the most widely used techniques in finite population sampling. Strata are disjoint subdivisions of a population, the union of which exhaust the universe, each of which contains a portion of the sample. Two of its essential statistical purposes are to: (1) allow for efficient estimation, especially in the case of stratification by(More)
ABSTRACT Let A be a population sub-domain of interest and assume that the elements of A cannot be identified on the sampling frame and the number of elements in A is not known. Further assume that a sample of fixed size (say n) is selected from the entire frame and the resulting sub-domain sample size (say nA ) is random. The problem addressed is the(More)
We consider estimation of finite population totals in the presence of non-response assuming that non-responses arise randomly within response classes. We compare in Section 1 two regression estimators: one of them is based on the adjusted for nonresponse probability weights and another is based on unadjusted weights. We show that when the auxiliary(More)
We consider variance estimation in the case of a calibrated estimator of a finite population total of a variable of interest y (the results can be generalized to more complicated finite population parameters, see Remark 3.3). An estimator is calibrated with respect to a particular variable x when the estimator is such as to yield the actual population total(More)
  • Michael Sverchkov, Alan H. Dorfman, Lawrence R. Ernst, Thomas G. Moerhle, Steven P. Paben, Chester H. Ponikowski
  • 2005
1. INTRODUCTION AND SUMMARY Most surveys have to deal with non-response. One of the approaches that is used to compensate for this is the correction of the initial weights of respondents through an adjustment factor. Under this approach, the entire sample is divided into cells of similar units, for example, representatives of a particular area,(More)