Minimax optimal approaches to the label shift problem in non-parametric settings. (arXiv:2003.10443v3 [math.ST] UPDATED)

We study the minimax rates of the label shift problem in non-parametric
classification. In addition to the unsupervised setting in which the learner
only has access to unlabeled examples from the target domain, we also consider
the setting in which a small number of labeled examples from the target domain
is available to the learner. Our study reveals a difference in the difficulty
of the label shift problem in the two settings, and we attribute this
difference to the availability …

arxiv math minimax non-parametric parametric shift