If you are thinking about getting a PhD in Economics, remember that it’s a big investment of time and money. Generally it’s best not to get a PhD at the same institution where you did your undergrad work. Spend some time researching the programs and choose the right graduate program for you.
The websites below offer some valuable advice to match your interests with specific programs. Check them out; then talk to the Econ professors at Mason with research interests similar to yours.
If you are thinking about getting a Masters in Economics, the perfect match in terms of fields offered may be much less important – i.e. you may want to choose a program that is near your home and/or work. Here are some good local alternatives:
George Mason University -- http://economics.gmu.edu/graduate/for-graduate
George Washington University -- https://economics.columbian.gwu.edu/graduate-programs
American University -- http://www.american.edu/cas/economics/MA-ECON.cfm
Johns Hopkins -- http://advanced.jhu.edu/academic/applied-economics/
The University of Maryland (College Park) offers a PhD in Economics, but not a Master’s degree.