College tuitions have increased at a rate of 2 or 3 percent more than general inflation over the past thirty years, according to Cornell University's Ron Ehrenberg. This means that the real cost of going to college has nearly doubled in that span. When a price increases by this magnitude, it is important not to lose track of the law of supply and demand. A clear implication of basic economics is that it is impossible to explain the increase in college costs by looking at only one factor. This type of sustained price increase can only occur if both demand...