I think the headline here is VERY misleading. While there are some schools that are clearly not very open to transfers, most have transfer acceptance rates that reflect their freshman retention rates—there is simply no room for additional students if there are not a lot of first-years transferring or dropping out. Many have transfer acceptance rates that are about the same as that for first-years (Columbia, Penn, Georgetown, for instance). And there are some notable exceptions—specifically Vandy (11% vs. 30%), NU (9% vs. 16%), USC (16% vs. 24%)—where transfer acceptance rates are actually substantially higher than acceptance rates for freshmen.