[uberman]

Sorry, I posted faster than I was thinking.

F1 students are limited by law to 20 hours a week and where I work, stipend responsibilities are similarly capped at 20 hours though though that is not a legal cap, just one that aligns with the international cap.

[mbauman]

There are both TA assistantships and research assistantships. As a graduate student researcher, your stipend "responsibilities" include research output.

[uberman]

I'm not sure where you are going with this. Certainly you can have a TA/RA/FA appointment and sometimes a combination of the three. At the university I work at, you should not technically be assigned more than 20 hours a week over those responsibilities. This blanket policy means faculty don't have to account for the potential visa limits of the individual students they work with.

Note though that an RA is research of behalf of a faculty member. Your RA and compensation for it is for assisting with that research. It is not for conducting your own research even if you dovetail it it to a larger research/lab project. In fact, you almost certainly need to pay for the use of the lab and project data via authorship (sometimes first authorship).

I'm not debating that this is fair. Going back to my original post though I'm just calling out that the total compensation package for phd candidates far exceeds their take home pay.