All the major high tech companies are setting up shop in Israel today, there is no drain. Israel's economy has also been surprisingly resilient and strong in the face of years of worldwide recession and depression.You know, this Nobel award brings up a real concern in Israel - it's "Brain Drain" and we, in the US are the benificiaries. The reasons aren't political, as far as I can tell from the article, but economical. Nobel Prizes for Israeli ex-pat scientists highlight rampant brain drain in Jewish state - The Washington Post
Iran has a similar problem. I point this out because I am constantly seeing parallels between Iran and Israel.
I'm not familiar with Iran's brain drain but I don't think the reason's are the same.
With Israel, according to the articles I read - it's very much an economic issue and a "state of the art" issue in terms of facilities. I would think that in Iran, there might be more factors such as academic freedom.
Iran on the other hand is collapsing under the pressure of international sanctions, all because it wants to acquire nuclear weapons to aim at Israel and Saudi Arabia. That's where the drain occurs.