Harvard University’s money managers collected tens of millions in bonuses by exceeding “easy-to-beat” investment goals even as the college’s endowment languished, employees complained in an internal review.

The consulting firm McKinsey & Co., in a wide-ranging examination, zeroed in on the endowment’s benchmarks, or investment targets. Some of those surveyed said Harvard allowed a kind of grade inflation when it came to evaluating its money managers.

“This is the only place I’ve seen where people can negotiate the benchmark they get compensated on,” read a “representative quote“ in the McKinsey report.

The McKinsey assessment offered an explanation of what it called the “performance paradox” at Harvard’s $35.7 billion endowment, the largest in higher education. Year after year, Harvard would report benchmark-beating performance while falling further behind rivals such as Yale, Princeton, Columbia and the Massachusetts Institute of Technology.

The April 2015 report, which has never been made public, spells out why the fund paid more than peers for lagging performance, as well as its management’s strategy for shifting course. Harvard said it has since revamped its compensation.