It's from the LSE website: BSc Economics: Applications 2008: 2,942 First year students 2008: 200
BSc Management: Applications 2008: 1,386 First year students 2008: 59
So as you can see, while the acceptance rate is around 6,8% for ECON, it is only around 4,3% for Management. I know both of them are ridiculously low but I wouldn't say that it's easier to get into Management