As an academic scientist in the USA, it is an amazing opportunity to work with bright people from all over the world. I feel lucky that I am from the place where this happens, and I don't personally have to travel overseas for it- but certainly would if I hadn't been from here. The scientists that come here from all over the world make discoveries that help everyone, but the companies that spin out of them usually end up US based and are a major driver of the economy. When we do hiring, it is only about 1/4 of the time or so I would say that we get a highly qualified applicant that is a US citizen.