http://www.americanthinker.com/2011/08/princetons_unobservable_assets.htmlThe above article highlights Princeton, but says that many universities are in the same situation. During the bubble a few years ago, they were convinced to invest way too much of their endowment into high risk investments. These investments are still not liquid - meaning they can't find buyers if they want to sell the investments. These investments also have unknown value, and the universities may be exaggerating their current value. Examples include 20 year investments in housing developments in Brazil, as well as hedge funds.
This is why several universities in 2009 with huge endowments on paper had to take out huge loans to pay their operating expenses.