Does City University London or Birkbeck U of L have a better reputation?

Which of the two universities- City University London or Birkbeck- has a better reputation among employers, students etc.? I'm an international student holding offers to each (so it's too late to consider other unis) and the specific courses are Economics (at Birkbeck) and Financial Economics (at City). I am more interested in the Econ program but will take the more specialized Fin. Econ course at City if the reputation is better (after all, I need a good job to pay off student loans). Rep is important as it's likely that I'll be returning to the states after I finish the course. Thanks in advance to all who reply....