So the way the PA 529 GSP specifically works, your earnings are indexed to full pay tuition costs, and actually if you don’t use the in-state publics, you can just choose whatever index works best for you. So like our S24 is at WashU, but we are using the Ivy League index for him, because that is higher than the non-Ivy private index.
Of course this is limited to PA residents, but these days with things like TIPS rates being positive real, it is reasonable to assume that if you invest in something like TIPS that will likely more or less keep up with college tuitions as well.
Of course the bigger picture here is as much about incomes as about asset returns. In 2025, a top 10% household income in the US was about $251K. Back in 2016, it was about $162K, so about 55% increase in 9 years. Cumulative inflation as measured by CPI over that time is about 34%. So, the top 10% in 2025 had more income in real terms than the top 10% in 2016, and that would particularly translate into more money for what I called “luxury” spending.
OK, so it is been a pretty great period for the top 10% sort of households with kids approaching college age. Solid increases in real incomes, and great asset returns. If they have shifted any 529s or such toward safer things like the PA 529 GSP or TIPS, they are probably pretty much fully funded for privates. But even if they are also cash flowing, well, those higher real incomes support a lot more cash flow.
OK, so back to Middlebury. Looks like in 2016-17, full COA was about $64K. 2025-26, it was about $94K. That’s about a 47% increase, so more than consumer inflation. But not more, actually a bit less, than the 55% increase in top 10% incomes.
Coincidence? I don’t think so.