I actually have only read the synopsis of the first one. I only included that link because it was mentioned in the article. And I had quoted from the article's

I actually have only read the synopsis of the first one. I only included that link because it was mentioned in the article. And I had quoted from the article's interview with that author. The one that convinced me previously was the second link, which was a pretty convincing natural experiment leveraging the fact that the visas are awarded by (randomized) lottery.