We come from successful private enterprises, leading financial institutions, groundbreaking nonprofits, innovative universities, market-shaping investment funds, pioneering public agencies, and major foundations. Strong partnerships must be sustained and strengthened between government, private investors, foundations, intermediaries, the social sector, and entrepreneurs, in order to develop a thriving impact investing marketplace. Today, investment areas once considered tenuous—from low-income housing to charter school development—have been proven, thanks to innovative partnerships between private-sector leaders and the government. And to reach its potential, this marketplace must provide investors with sufficient data to make informed investment decisions.