I was a teaching assistant in grad school. I suppose I wasn’t a very good TA, but I was trying. I somehow avoided being fired. I actually enjoyed talking to my students and seeing them learn math, but I was too tired most of the time to do a very good job. Studying and teaching together came out to about a 50- to 60-hour week.
Why did I go grad school at all? Well, I sure didn’t have any family fortune to fall back onto. My father was a farmer and a factory worker and my mother was a housewife. I was one of eight children. The amount I can expect to inherit from them someday comes to about three months of my present salary.
I was very good at math, so getting a degree in math in college was the obvious thing to do. What could I do with such a degree though? I could teach high school, if I spent another year on education courses, but I can’t imagine that I would have liked teaching high school. I could have become a programmer, I suppose, but this was in the '70’s, and pay wasn’t as good for programmers. Besides, it was already clear to me that I wouldn’t be a very good programmer (and in fact I’m not now, in the parts of my job where I do programming).
I had gotten interested in linguistics though, so I applied to grad schools in that subject and asked if I could work as a math TA at the same time. I could see myself teaching linguistics at a college once I got my Ph.D. I slogged through the first year studying and teaching and survived somehow. The second year I survived by working part-time in a departmental library and getting some cash and some loans. The third year I had already become discouraged with making it to the Ph.D., so I only took one course during that year, one which would finish my masters, and I worked full-time in the university library. By this time the department told me to find another career.
I transferred to another university and started work on a math Ph.D. I worked as a TA during the time I was a student there. I wasn’t very good, I suppose, but I survived somehow. By the end of the third year, although it was clear that I could make it to the masters degree, it was also clear that it was going to be hard work making it to the Ph.D. So I got my masters and took some courses towards a third masters in computer science. I gave up on that by the end of the fourth year, but by that time I got an offer to work as a mathematician at a government agency. For the last 18 1/2 years now I’ve worked at a 40-hour-per week job that now pays me 60% more than my father made working 50 to 60 hours per week.
I suspect that this same story could be told of most people who work as TA’s. With a graduate degree, you can work at an interesting job that pays pretty well; without it, you work at a boring one that doesn’t pay well. To get a graduate degree, you need to work as a TA unless you come from a family with money. (If you’re a superstar in college, you might be able to get a fellowship.)