Wasserstein Bipolarization Index // Computation of the Wasserstein Bipolarization Index as described in Lee and Sobel (Forthcoming) doi:10.48550/arXiv.2408.03331. Provides both asymptotic (Sommerfeld, 2017 https://ediss.uni-goettingen.de/bi tstream/handle/11858/00-1735-0000-0023-3FA1- C/DissertationSommerfeldRev.pdf?sequence=1) and bootstrap methods (Efron and Narasimhan, 2020 doi:10.1080/10618600.2020.1714633) for calculating confidence intervals.