Any strong graduate program in economics will require prospective Ph.D. candidates to have a solid quantitative background. You are urged to take, at a minimum, the complete sequence in Calculus offered by our Math Department, which includes Calculus I, Calculus II, Multivariable Calculus, and Linear Algebra. Naturally, any coursework beyond this sequence will be additionally useful in preparation for graduate school. If you are bound for a top program, for example, you should try to complete a full year of Analysis before graduation.
Most programs will state that majoring in Economics is not a prerequisite for admission. You will find, however, that Honors-level Micro and Macro Theory at Georgetown will give you a rigorous introduction to the economics topics you will encounter in graduate school. If you excel in the Honors courses here, you will be better able to tackle these issues at a higher level after graduation. Likewise, you should also strive to master Economics Statistics and Econometrics, since these are the essential foundation for graduate study.
Many graduate programs will expect that you have honed your research skills prior to entering graduate school. You should bear this in mind when completing your senior thesis. The ability to work with primary data sources is important in any field, but especially true in economics.
You can expect to complete a full-time Ph.D. program in Economics in a minimum of four years. In general, the first year of study will consist of required courses in microeconomics, macroeconomics, and econometrics while the second year will allow you to specialize in a field or fields of your own interest. Subsequent years in the program will typically be spent researching and writing your dissertation.
You may wish to look at the Georgetown University graduate program in economics for more information about the structure of a typical graduate program. Furthermore, the National Science Foundation provides research fellowships for American citizens and permanent residents to pursue graduate studies in a variety of fields, including economics.