> The professor also only hired visa applicants to have extra leverage over them.
For any postdoc that thinks the university has leverage for this reason, if you are able to get a H1B, you can switch employers easily. You are not stuck at whichever company sponsored you.
* My understanding is that universities prefer J-1 visas in almost all cases [1][2], and such visas are not portable.
* H-1B is more flexible than J-1, but still not as flexible compared to a green card. In particular, the new employer has to fill out a new application, pay the fees, etc. Also, universities are exempt from the H-1B cap, but other employers may not be.
False. H1B visas given to work for a university are "cap exempt." They allow to work for universities and other nonprofits only. H1B visas to work for a for-profit company can only be obtained through a lottery.
There's more nuance here. There're ways to "port" your H1B to another company (incl. while working part-time with one leg at a non-profit and another at a startup), but few want to go that route because of all the other bullshit we already had to go through.
I don't think we are in disagreement here. My main point is that many feel "pressure" from their employer. Knowing and keeping your options open and ready to act on them, even at other universities, empower all workers.
I think every single person in my lab was on a J-1. This was in the 2006-2010 timeframe, the H1B process for post-docs may be different now. I can think of one case where a researcher burned out on 80 hour weeks, got divorced, and was asked to leave after their productivity dropped. They didn't have much choice other than to go home to their home country immediately.
We also had an untenured research scientist who did all of the PI's work and grant writing. After two 110+ hour weeks getting three grants written for several million dollars they went home to enjoy the weekend and dropped dead of a heart attack at 42. I miss him.
For any postdoc that thinks the university has leverage for this reason, if you are able to get a H1B, you can switch employers easily. You are not stuck at whichever company sponsored you.