Robust estimators of the generalized log-gamma distribution

We propose robust estimators of the generalized log-gamma distribution and, more generally, of location-shape-scale families of distributions. A (weighted) Qτ estimator minimizes a τ scale of the differences between empirical and theoretical quantiles. It is n 1/2 consistent; unfortunately, it is no...

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Autores principales: Agostinelli, C., Marazzi, A., Yohai, V.J.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00401706_v56_n1_p92_Agostinelli
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Sumario:We propose robust estimators of the generalized log-gamma distribution and, more generally, of location-shape-scale families of distributions. A (weighted) Qτ estimator minimizes a τ scale of the differences between empirical and theoretical quantiles. It is n 1/2 consistent; unfortunately, it is not asymptotically normal and, therefore, inconvenient for inference. However, it is a convenient starting point for a one-step weighted likelihood estimator, where the weights are based on a disparity measure between the model density and a kernel density estimate. The one-step weighted likelihood estimator is asymptotically normal and fully efficient under the model. It is also highly robust under outlier contamination. Supplementary materials are available online. © 2014 American Statistical Association and the American Society for Quality TECHNOMETRICS.