November 1, 2012 — When it comes to shoring up the nation’s economy, Franklin D. Roosevelt, Warren G. Harding and Rutherford B. Hayes top the list, while Chester Arthur, Herbert Hoover and Martin Van Buren rank at the bottom, according to a new study by the Georgia Institute of Technology. The first-of-its-kind study analyzed up to 220 years of data to estimate an economic “grade point average” for presidents who served from 1789 until 2009.