In some stock markets, PE ratios are higher than long-term averages, in spite of the fact earnings prospects are restrained by relatively low growth outlooks. Also, the gaps between housing and consumer price indices in some advanced countries, such as Switzerland, Australia, and Norway, have been rising rapidly in the last few years.
A final manifestation of costs is the possibility that negative rates hurt banks, as well as money market funds and other non-bank financial institutions such as insurance companies, with no clear payoff in terms of economic growth.