Even at places where the pay scale is set at the departmental level, professors have discretion on whether they want to pay you over the summer. That's 1/4 of y

Even at places where the pay scale is set at the departmental level, professors have discretion on whether they want to pay you over the summer. That's 1/4 of your salary. Also, funding comes straight from the professor. If your advisor decides they don't have funding, you're out of luck and working on the side, unless your department is nice enough to give you a teaching assistant job.