European governments see the demographic timebomb coming, so they massively incentivize their citizens to invest in a primary residence, treating it as forced savings. This inflates local real estate values to ridiculous levels, especially while interest rates are low.
However, incentivizing your citizens to take leveraged bets (big mortgages) on a single piece of real estate is...not great.
This means the investment portfolio of the average European citizen is ONE specific apartment (zero diversification), and negative yielding sovereign bonds (via government pension funds).
Since most European mortgages are not fixed rate, it will be interesting to see what happens as interest rates start rising in Europe.
While the bonds will start paying better interest, that mortgage exposure might start to wreak havoc on the average citizens finances...