The market impact appears to be negligible. At least not as large as factor as implied or popularly claimed.
How many foreign nationals own property in Vancouver? How many of those properties are unoccupied? I can't remember where I spotted reporting on those two questions, but I wouldn't be surprised if the city publishes real estate transaction data such that the number of foreign purchases can be gathered. I remember a very small portion reported.
https://www.thestar.com/vancouver/2018/06/24/in-one-of-west-...