Top administrators in the University of Massachusetts system were compensated less than the average public school president, according to the Chronicle of Higher Education’s annual survey of executive compensation at 214 public colleges. UMass president Robert L. Caret earned $535,750 for the 2012 fiscal year. Caret’s compensation ranks 69th in the study. Robert C. Holub, former chancellor of the Amherst campus, was paid $417,375, earning him a ranking of 120th. Chancellor Martin T. Meehan of UMass Lowell ranked 145th in the study, with a salary of $367,800 for fiscal 2012. J. Keith Motley, who heads the Boston campus, earned $277,439, making him 190th. The highest earner was Graham B. Spanier of Pennsylvania State University, who resigned amid the child sexual abuse scandal at the college, with a salary of $2,906,721.