Patrick Collinson:

Berlin has emerged as the frothiest property market in the world, with the city engulfed by expensive highrise developments and speculative buying that threatens its traditionally low rents and hip arts scene.
 
 Prices in Berlin jumped by 20.5% in 2017, according to the property consultancy Knight Frank, with other German cities also displacing cities in China in terms of rising prices.
 
 Berlin, Hamburg, Munich and Frankfurt were ranked in the top 10 in the world for price rises, with several Dutch cities not far behind.
 
 London was ranked 101st, with a 2% gain, while Auckland in New Zealand, once gripped by a property frenzy, dropped to 99th with a 2.2% increase.
 
 But attempts by the authorities in Vancouver to quell its soaring prices – including a 15% foreign buyer tax – appear to have stalled, with prices in the Canadian city jumping by 16% in 2017, the fourth fastest in the world.