Mercer is the director of the Mercer Family Foundation, a charitable non-profit organization founded in 2004. She is the founder and chairman of Reclaim New York, a non-partisan, non-profit organization dedicated to advancing a state-wide, grassroots conversation about the future of New York, its economy, and its people. She serves on the boards of a number of other non-profits, including the Media Research Center, the Calvin Coolidge Presidential Foundation, the Moving Picture Institute, and the American Museum of Natural History. With her sisters, she owns and runs Ruby et Violette, an online gourmet ice cream and chocolate chunk cookie company.
Mercer grew up in Westchester County, New York, the second of three girls. She attended Stanford University, where she received a dual bachelor’s degree in biology and mathematics and a master’s of science degree in operations research and engineering economic systems. She worked as a trader for a New York financial firm before retiring to raise her four children.