The property market is affected by a wide variety of factors. The Government published an assessment of the 2014 changes to Stamp Duty Land Tax in 2015. It showed that in the year after the reforms, the number of residential property transactions above £1m was the same as the year beforehand. The analysis can be found at:
Recent statistics show that residential transactions greater than £2m are 9% lower in Q2 2017 than Q2 2014, while transactions between £1 and £2 million are 19% higher.