Editor's Note: This opinion piece has been previously published in Engage Magazine, a publication of the Steve Sinnott Foundation in the UK. 

For some time now, evidence-based development has been all the rage. Rigorous evidence about whether an intervention or program works, and for whom and why -- and, by caveat, whether aid money is effectively spent -- is a growing focus of attention. We have seen tremendous growth in so-called impact evaluations of social development interventions and policies to understand whether they work, and significant interest in considering rigorous evidence in making program and policy decisions. In an era of tight budgets, skeptical voters, and big aspirations, governments the world over are being challenged to demonstrate the value for money of their programs. Given that billions of dollars are spent on social development around the world, this is a welcome and important trend.

But it is easy for this conversation to miss an important element of evidence based development: The process by which results about “what works” translate into action. How do programs and policies that have been proven to work based on rigorous research studies, in fact, reach millions if not billions of people? What is that path to scaling what works to people who need it most? Its almost certainly not the case that evidence presented in policy briefs and journal articles is enough for busy, risk averse firms and governments that struggle with complexity to go on, no matter how committed they are to cost effectiveness. There is a missing middle, a gap, in the simplest “theory of change” of evidence-based aid and development.  

The Zeitgeist of Evidence-Based Policy 

The growth in the ‘rigorous evidence’ zeitgeist has been noticeable:  There are research organizations, many affiliated with universities and networks of renowned development economists, that are devoted to ‘finding what works:’ There is the venerable Abdul Latif Jameel Poverty Action Lab (J-PAL) at MIT, there is Innovations for Poverty Action, and the Center for Effective Global Action (CEGA) at the University of California at Berkeley. There is a growing number of funders that have made evidence-based development a cornerstone of their grantmaking:  DFID has a number of initiatives that focus on evidence in making decisions about interventions; USAID, the US development agency, has the Development Innovation Fund that focuses on rigorously evaluated and promising interventions, and there is a brand-new collaborative of donors, the Global innovation Fund, that does the same. There are research networks like the Africa Evidence Network, a community for policy makers and practitioners that share evidence-based programs and policy across Africa.

Governments Take Note  

And governments are starting to take note as well: The Indian state of Gujarat reformed its environmental auditing system just last month based on findings from a large-scale rigorous evaluation study conducted in partnership with economists affiliated with JPAL. With our support, Kenya started a national school-based deworming program in 2011 and India followed suit this year with a national program that is targeting 241 million children for deworming to end the public health threat of parasitic worms. Deworming is a textbook example of a evidence-based program and policy. There is a significant body of rigorous evidence by researchers that shows that treating kids for worms helps them feel better, no surprise, but also supports weight gain, brain development, and productivity in school and later in life.

Other organizations like Give Directly’s direct cash transfer programs are similarly based on rigorous evidence. We are running Dispensers for Safe Water, a well-evaluated rural water service that allows users to chlorinate their drinking water directly at the water source at no cost.  

How do we get from what works for a few to millions? 

But the question remains: How do we get from a study on the effect of deworming in school attendance in Kenya published in 2004 to 241 millions children targeted for deworming in India in 2014? How do we get from a trial on the effectiveness chlorination at the water source affecting a few hundred people to serving more than three million people with a sustainable service with good operational and business plans in East Africa?

What is the path from promising evidence in a research study to sustainable programs that reach millions?

We at Evidence Action believe that reducing poverty and spurring growth in developing countries requires strategic, high-value investment of scarce resources. We develop and de-risk business models for such programs -- such as supporting governments with national deworming program and scaling a sustainable rural water service -  that allow tens of millions of people to be served, and the return on investment to be measured. We bridge the gap between rigorous research and pilot programs on the one hand, and institutionalized programming on the other.

We are now pressure-testing promising new interventions to see whether they are suitable for scale-up. We take on questions such as whether a program is grounded in rigorous evidence of effectiveness; has a credible path to a cost-effective service delivery model that contextualizes essential research results without sacrificing impact; has a credible path to serving millions of people in the event that the business model can be fully articulated; and does not displace activities or investment that would otherwise be made by others.

Our goals is to have a demonstrated track record of bringing five to seven promising approaches to large scale (serving tens of millions of people with improved health and well-being), using robust business models. We also want to share lessons, strategies, and tools to seed further scaling of evidence-based approaches by others.

We love the fact that rigorously-evaluated evidence of impact is beginning to be a significant criterion in social development programs and policies worldwide. But let’s not rest there. Let’s also show that what has been proven to work for a few can do so cost-effectively and sustainably for millions of people.