Their work allowed economists to measure economic aggregates and prices across nations and over time.
"At his core, he was concerned with how to measure and understand human well-being through income and wealth, and how to make people's lives better," said his son John Summers, of Merion.
Lawrence Summers, a former Treasury secretary who is also an economist, said that when he was growing up, his father used Phillies box scores to expose him to economics.
"Nothing was more important to me as an 11-year-old than baseball, and so we studied baseball statistics," Lawrence Summers said. "He was always interested in how statistics and data could illuminate almost anything."
Born in Gary, Ind., Mr. Summers received a bachelor's degree from the University of Chicago and a doctorate from Stanford University. He taught at Yale University before joining Penn in 1960 as an economics professor. He retired in 1991.
During his years in Washington, Lawrence Summers said, his father had "strong opinions" on how the Clinton and Obama administrations presented analysis and policies, and "sometimes on what those policies should be."
But he added that his father "was strongly progressive and thought it was imperative to make sure there was a focus on the poor."
"He was an exceedingly generous man," Lawrence Summers said. "He and my mother would host every student he taught and invite them to come to their home."
In addition to his wife of 59 years and sons Lawrence and John, Mr. Summers is survived by another son, Richard, and seven grandchildren.
Services will be at 10 a.m. Thursday, April 19, at Beth David Synagogue in Gladwyne.
Contact staff writer Jennifer Lin at 215-854-5659 or email@example.com, or follow on Twitter @j_linq.