Colleges face their highest expense growth in over a decade as rising costs combine with wage inflation, labor shortages and a push to hire, according to two new reports issued this week by Moody's Investors Service. At the same time, volatility has returned to the investment market, and recent public funding increases are waning, Moody's said. Colleges also face mounting enrollment uncertainty that raises risks for tuition-dependent institutions that lack a national brand and deep pockets.