• Bernoulli
  • Volume 24, Number 4A (2018), 3147-3179.

Wide consensus aggregation in the Wasserstein space. Application to location-scatter families

Pedro C. Álvarez-Esteban, Eustasio del Barrio, Juan A. Cuesta-Albertos, and Carlos Matrán

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We introduce a general theory for a consensus-based combination of estimations of probability measures. Potential applications include parallelized or distributed sampling schemes as well as variations on aggregation from resampling techniques like boosting or bagging. Taking into account the possibility of very discrepant estimations, instead of a full consensus we consider a “wide consensus” procedure. The approach is based on the consideration of trimmed barycenters in the Wasserstein space of probability measures. We provide general existence and consistency results as well as suitable properties of these robustified Fréchet means. In order to get quick applicability, we also include characterizations of barycenters of probabilities that belong to (non necessarily elliptical) location and scatter families. For these families, we provide an iterative algorithm for the effective computation of trimmed barycenters, based on a consistent algorithm for computing barycenters, guarantying applicability in a wide setting of statistical problems.

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Bernoulli, Volume 24, Number 4A (2018), 3147-3179.

Received: October 2016
Revised: May 2017
First available in Project Euclid: 26 March 2018

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impartial trimming parallelized inference robust aggregation trimmed barycenter trimmed distributions Wasserstein distance wide consensus


Álvarez-Esteban, Pedro C.; del Barrio, Eustasio; Cuesta-Albertos, Juan A.; Matrán, Carlos. Wide consensus aggregation in the Wasserstein space. Application to location-scatter families. Bernoulli 24 (2018), no. 4A, 3147--3179. doi:10.3150/17-BEJ957.

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