“…The Bayesian literature, having access as it does to posterior simulation schemes, has entertained more sophisticated (including time-varying) weighting schemes, in which predictive performance-quantified by a range of different problem-specific loss measures-influences the posterior up-dates of the weights. Key work here, including some also driven by the criterion of calibration, includes Billio et al (2013), Casarin, Grassi, et al (2015, Casarin, Leisen, et al (2015), Casarin et al (2016), Pettenuzzo and Ravazzolo (2016), Aastveit et al (2018), Bassetti et al (2018), Baştürk et al (2019) and Casarin et al (2019). 13 In principle, any of the above combination schemes could be used to construct the predictive class P t , with the chosen measure of predictive accuracy used to define the update in (2).…”