Generally it seems that higher interest rates have often made bonds an attractive investment. This may lead people to forsake stocks in favor of lower risk returns with improved yield. (Not sure this will be the case this time with yields still so low.) Implications of this study appear to be longer-term in nature than we usually see. To help visualize how this edge has played out over time I have pasted the equity curve using a 50-day exit strategy.
This one looks very similar to the 20-day exit strategy. In this case the downside edge didn't begin to exert itself until the 1970s but it too has persisted lower for a long time.