The nascent impact-investing field has sparked intense debate as the private equity community questions whether or not funds seeking to do social and environmental good can also produce strong returns. Impact investing is a relatively new term used to describe an investment approach that aims to produce positive social, environmental and governance changes. The paucity of data and the few standards on how to measure this impact have made the space a lightning rod for criticism. The researchers were able to obtain verified cash flow and valuation information on a portion of the data set—170 portfolio companies backed by 16...