In the current situation, if the banks drastically increase credit spreads, their borrowers are likely to go bankrupt and the banks will have to pay the price in the end.
And, most importantly, over longer samples it is found to be the most accurate predictor (Alquist and Kilian, 2008). However, other measures of the risk premium in oil futures are also conceivable and used in practise (in particular in central banks’ forecasts).