On William Marina's post a week ago looking at Martin Wolf's commentary on world interest rates, I would not argue that real interest rates are that low. Real interest rates, best defined by looking at inflation-index securities, have had rates rising back towards 2% lately. With import prices rising faster than expected of late as well, bond traders are getting increasingly bearish. Yet there isn't a wide sell-off yet, so if there's a bubble it's proven resilient so far.