College has a big impact on a family’s long term finances. It’s a large expense that comes relatively quickly in the family financial lifecycle, so there isn’t a lot of time to see salary improvements and allow for beautiful, beautiful compound interest to do its magic. Most of us know college prices have gone up a lot faster than the Consumer Price Index, our general benchmark for inflation. But how much faster? What should you and I assume today about the cost of four-year college in 18 years?