One topic using publicly available data would be to measure the effects of the EURO on the EU countries economies. This study would allow us to see whether or not the EURO has had a positive on all of the countries economies or if there is a varying amount of benefit for France and Germany while countries like Greece suffer. We can look at historical data of their growth rates and how they changed over time. and how their GDP has been affected comparative to other countries in the EU. There is a site that could aid in this: http://www.ecb.int/stats/html/index.en.html Possible hypothesis tests would be something along the lines of, do each countries get the same benefit. Ho they do. Ha they do not. They are doing relativly worse now then they were before. Ho: they're doing the same. Ha they are doing worse.
A study that could be collected would be one examining the effects of private college education on getting into higher end graduate schools. You would need to new admittance into high end grad schools. (Schools ranked in the top 50 grad schools) and check which colleges they came from, what their GPA was and scores to get in. You could compare the difference between the public school scores needed and the private school scores needed to get in.