Sure, though that study was done in Vancouver, and their laws about real estate records being public record might be different than California or the other U.S.

Sure, though that study was done in Vancouver, and their laws about real estate records being public record might be different than California or the other U.S. states (the article mentions only the methodology regarding Chinese names). You asked if there was a dataset that could be used in studying impact of foreign buyers; I was just pointing out that the government most definitely collects data of real estate transactions and generally makes it publicly available in the U.S.