How will you know where you studies will lead you and how much you will earn later in life?
1. Do your research on salary levels for your field and school. There is plenty of information online regarding salaries of grads of each school, especially if it is a US school. This will give you a good general indication,. See Payscale.com or the college ROI report.
2. Do your research on percentage of employment post-graduation – understand your chances of actually finding a job after you graduate. The schools themselves and other accessible information sources are available so you can understand this factor.
3. Make a decision trying to foresee the future. One way you can do this is by consulting with a "future you" - a mentor from a background similar to yours who has been through the process and can guide you to make the right decisions. You can find people like that on the GradTrain website.
Our global society definitely needs sociologists, social workers, historians etc., but when you make decisions on your field of study, you need to see how this will impact your life. If you find a job in academia and stay in the US, you may be able to sustain yourself, though if not, you may need to change careers at a later age if you cannot sustain yourself. The key is to make your decisions based on facts on just on gut feelings.
Below is an infographic regarding the 5 best schools in the United States in terms of return on investment (ROI).