Impact Investing and Evaluation: A Conversation with Andy Marshall

Andy Marshall describes his evolution from traditional philanthropy—what he calls “pay-and-pray”—to impact investing, a model that blends financial return with mission-driven goals. This approach offers more than recycled capital; it empowers nonprofits to focus on outcomes instead of short-term fundraising cycles. By aligning investments with social performance, impact investing can elevate high-performing organizations and offer flexible, long-term support to scale their impact. Sara Bayless underscores the role of evaluation in this model, noting how customized metrics can help organizations stay grounded in their missions while delivering meaningful, measurable change.

Together, Andy and Sara advocate for a future in which rigorous evaluation is the norm in impact investing, not an afterthought. Despite the growth of the field, a vast majority of impact capital still lacks ties to demonstrable social outcomes. The Center for Social Investment was created to change that—to bring discipline, transparency, and data into funding models. By applying proven evaluation tools like theories of change and quasi-experimental designs, they aim to quantify social return, close the gap between intention and impact, and shape a sector that is as accountable as it is aspirational.