Katherine Geier wrote on the topic.
So why, then, don’t we see more of this type of immigration here? A simple application of the principle of cui bono gives you your answer. Highly educated elites after all, are the people making these policies. You are not likely to see, for example, many economics professors running around arguing themselves out of a job — even though I am sure virtually all of them are highly replaceable.I totally lose it in comments.
I'm going to start seriously and get silly. Seriously when you write "income inequality" you mean "income inequality in the USA". Allowing high skilled immigration to the USA would cause increased inequality within their countries of emigration and increased inequality across nations, since the USA is still the richest large country.
Notably higher education in most countries is even more highly subsidized than it is in the USA (I'm not saying too highly subsidized -- I think the USA should subsidize more to equalize opportunity and to increase the supply of highly educated people which would reduce inequality in the USA and world wide). The popular proposal is to take advantage of education provided at the expense of foreign taxpayers. This is entirely in keeping with US public opinion generally -- the one program US adults most want to cut is foreign aid. But that doesn't make it morally right.
I support free immigration which means I support free immigration of MDs too (as a matter of respecting the human right of people to live where they please and out of opposition for hereditary privilege including exclusive US citizenship). But I am disturbed by complete indifference to the interests of anyone outside of the USA.
"You are not likely to see, for example, many economics professors running around arguing themselves out of a job —" but one is typing this comment. To be exact, I argue that it is a mistake to employ me, not argue in a way which puts my hold on my tenured job at risk.
I teach labor economics in Rome. I just gave a lecture on migration and wages (I didn't have anything non obvious to say). I note that Italy is very very open to immigration by economics professors. So, for that matter, is the USA (ever heard the phrase "brain drain"). Visas and such are a minor issue. The faculties of elite Universities in the USA include many immigrants.
Baker is talking about professional licencing which is different, but US economists are perfectly willing to compete with people born overseas.
Consider this list of top young US economists -- recpients of the John Bates Clark medal "The John Bates Clark Medal is awarded by the American Economic Association to "that American economist under the age of forty who is adjudged to have made a significant contribution to economic thought and knowledge"" Note the word "American" in the title. Of the past 11 recipients, 5 were born outside of the USA (4 outside of the Americas): David Card (Canada), Andrei Shleifer (then USSR -- in particular Russia), Daron Acemoglu (Turkey), Emanuel Saez (France) and Esther Duflo (France). Shleifer was not a highly educated immigrant -- he didn't have a high school diploma when he immigrated at age 15 in 1976.
This is not a field which exclude immigrants. Your observation that US economists do not argue that they should have to compete with immigrants is valid for the simple reason that it goes without saying being the current and unquestioned policy.