1. I'm not sure this is true.

2. Even if it is, housing is actually an amazing American export: http://www.slate.com/blogs/moneybox/2013/05/19/exporting_hou..., though it's rarely recognized as such outside of the literature.

Are there any pieces of data quantifying how much of an effect this is having in San Francisco?

There's a very small amount of data available. It suggests that international purchasers are around 6% of the total cash buyers of real estate.

https://news.ycombinator.com/item?id=11270279

It is somewhat frequent for the buyer to be local, and the money to come from overseas. Son buys a house with his dad's dubious-origin money.

And given the lack of required information & intentional ignorance ("so, Mr. Boriskypov, would you describe yourself as an oligarch?") I'm not sure how that dataset could reliably identify "international" purchasers.

The dataset was from a real estate company's reports from individual realtors. I'm confident the realtors know the origin of money.

I think a more appropriate criticism would be to focus on the narrow class of purchases (cash only) or small sample size (n=300, though the company represents 10% of the real estate market in the SF Bay Area). Unfortunately, it's the only published information I could find.

This article throws around numbers like 15% for the Bay Area (not US), in 2014. Not sure about SF. http://www.sfgate.com/business/networth/article/How-and-why-...

Is the information public? Equity investments are visible in SEC filings, but can this even be quantified from public data?

Keep in mind neither tech nor entertainment was ever California's main industry. It is and always has been real estate. Money from real estate flows down stream into MANY pockets.