Central banks may need longer to lower inflation and a fresh bout of financial turbulence could make the process even more protracted, the International Monetary Fund warns. London Business School economics professor Richard Portes said, euro zone housing markets appear to be "freezing up" as transactions and prices fall. And knock on effects, from inflation pressures to risk aversion in case of a major escalation, could have far reaching consequences for countries and corporates already feeling the heat from rising rates.