hi, I plan on applying for PhD programs in public affairs field too. And I also take a look at programs in business school such as strategic planning. However, I notice that several business schools need GMAT score instead of GRE, not for sure but most likely. according to your math courses in undergrad level, I think GRE quantitative high score might help. BTW, I think Duke PhD program has econ track and your profile seems appropriate to apply this school. I also want to go schools that concentrate on quantitative tools. I got straight A in calculus, linear algebra, statistic but lack the course of micro/macro econ which I really need to make up for....