[wslh]

> I'd say the biggest reason is immigrants.

Yes. Israel received top scientists from ex-soviet countries that helped to shape the country. Even in the pre-israel era, many people with science knowledge did agricultural jobs in search of an ideal.

[MrVitaliy]

Those ex-soviets are mostly jews who finally seized an opportunity to live somewhere else, outside of iron curtain. Many of them also showed up in US, see Sergey Brin.

[wslh]

I didn't understand your point.

If you are jewish it is straightforward to move to Israel, but it is a lot more complex to move to US legally. So, Israel received a lot of people from the diaspora giving them instantaneous citizenship plus economic incentives to move.