Indeed, such a shift – or other investors’ (eg hedge funds) anticipation of it – is commonly cited as a “special factor” explaining what appear to be excessively low levels of global longterm interest rates.
But even if such a shift is plausible in countries where equity allocation in the investment portfolios predominates (for example, in the US, the UK or Canada) empirical evidence of such a closing of the duration gap is neither clear nor uniform across countries.