Other money managers joining universities sought Mr. Swensen’s advice. He always suggested that they keep their offices on campus if possible, and he was sensitive to matters that students brought up, like climate change. Students have continued to push Yale to take a stronger stand on the issue.

Mr. Swensen acknowledged that greenhouse gas emissions posed a grave threat and asked managers to consider the financial risks of climate change, particularly if the government imposed carbon taxes. The investment office recently estimated that 2.6 percent of the endowment is invested in fossil fuel producers, a multi-decade low, and that it expects that decline to continue.

In 2018, Mr. Swensen said Yale would not invest in outlets that sell assault weapons. Most recently he encouraged endowments to hire more women and members of minorities.

Over the years he was a trustee or adviser to a host of institutions, including the Brookings Institution, the Carnegie Corporation, the Courtauld Institute of Art, the Chan Zuckerberg Initiative and the states of Connecticut and Massachusetts.

Mr. Swensen’s first marriage, to Susan Foster, ended in divorce. In addition to Ms. McMahon, he is survived by three children from his first marriage, Alexander Swensen, Timothy Swensen and Victoria Coleman; his mother, Grace; two brothers, Stephen and Daniel; three sisters, Linda Haefemeyer, Carolyn Popp and Jane Swensen; and two grandchildren. He lived in Killingworth, Conn.

Mr. Swensen was as concerned about the small investor as he was about his endowment. In his book “Unconventional Success: A Fundamental Approach to Personal Investment” (1995), he advised people to keep their costs low and to stick to exchange-traded funds, which invest across an entire index of stocks, rather than investing with money managers or mutual funds that select individual stocks, and where the costs can erode profits. It was virtually impossible for the average investor to get into the best private funds, he said.

Alex Traub contributed reporting.