1. The number of enrolled college students slipped 1.3% this fall compared with a year earlier, representing a loss of 231,000 students. So what accounts for lower college enrollment? Demographic changes. The number of high school graduates is stagnating, with overall graduation rates expected to drop in the next decade. The rising cost of college. The price for a private, four-year college is about $41,000 per year, or about double the cost in the mid-1980s. A growing economy. Some high school students may be deferring or opting against college due to the low unemployment rate and the availability of jobs.