This article was published by McKinsey & Company in honor of the Skoll World Forum.

In the past quarter-century, the world has made unprecedented gains in reducing poverty and expanding opportunities for human beings to flourish. Sustained economic growth in countries like China and India has lifted hundreds of millions out of absolute poverty and transformed global economic prospects. And progress reaches far beyond the powerful middle-income states. In sub-Saharan Africa, a dozen countries have seen their economies expand by more than 5 percent annually over the past decade, despite the global crisis.

In many settings, development is working. Yet the gains have left too many behind. An estimated 1.3 billion people still survive each day on less than the price of a daily newspaper. And progress in critical areas remains fragmentary. China leads the world in key aspects of green development. Yet the recent pall of pollution over Beijing’s streets reminded us that in China and across the world, bold advances on some fronts are weighed down by outmoded approaches that cannot be sustained.

Even when governments have robust development policies in place, results can be frustratingly inconsistent. Moreover, we are often unable to account for this inconsistency. We’re at a loss to explain why a given development program succeeded brilliantly in one setting, while a similar strategy in a neighboring country cost more and delivered less.

For countries, the inconsistency in development results carries a high price. It makes prioritizing and sequencing development interventions even more difficult. And it means that, too often, investments in development don’t bring the returns that policy makers want and that citizens expect.

In the private sector, competition eliminates firms that fail to execute. For successful companies, a deep understanding of delivery is essential because it affects their bottom line. Many of us working in development have envied Unilever’s ability to deliver its personal-care products reliably to the remotest African villages—where essential medicines and schoolbooks are often missing from the shelves.

The hallmark of delivery excellence is consistency.

Companies achieve this through a relentless focus on the details of execution, along with a capacity to adapt as conditions change. Development agencies need to learn from the seriousness with which the most successful private companies have tackled delivery.

In the years ahead, allying the strengths of the public, private, and civil-society sectors will be critical to getting delivery right and achieving development goals. Development agencies don’t assume that state action alone will bring prosperity. World Bank Group economists recently showed, for example, that nine out of every ten jobs in developing countries are created in the private sector. On the other hand, governments set the rules. They offer a framework for communities to decide how “prosperity” ought to be defined. They mandate that essential public goods like health and education must be delivered to all citizens alongside power, water, and other tangible commodities.

Over the past few centuries, evidence-based delivery systems have revolutionized our lives. They have shown us what can work. The problem is that we still lack a framework for systematically understanding what does work in a given time and place, and for holding officials accountable to that standard. Now development agencies can fulfill their public trust by creating a science of delivery that will compile global delivery knowledge and mobilize it for practice.

An effective science of delivery would ensure that all schools learn from the schools where children learn best. It would mean that people don’t just receive healthcare but actually become healthier, while high-performing hospitals and clinics serve as models and resources for practitioners elsewhere. Such a science would nurture the vibrant communities among implementers across countries and regions, in all development sectors. These communities would enable joint problem solving and would continuously link local action to global evidence.

I see four dimensions to the emerging science of delivery:

  • First, it will support frontline implementation by collecting local experience and feeding that knowledge back into practice.
  • Second, it will teach delivery skills based on the experience of the most successful practitioners.
  • Third, it will incorporate prospective research (“clinical trials”) to spur innovation and evaluate new interventions.
  • Fourth, it will develop theoretical and analytical frameworks that can help explain and adapt successful approaches to solving delivery problems.

Building the science of delivery will be a collaborative process. People have argued for decades that the top-down transfer of technical know-how from wealthy countries to poor ones often falls short. Delivery knowledge will flow in all directions, especially along horizontal, south-south pathways.

The science of delivery will take time to create, and it will never really be complete. At the dawn of the modern era, the British physician Thomas Sydenham dreamed of a system that would “reduce all the species of epidemics into classes, according to the variety of their appearance … explain their peculiar signs, and point out a proper cure for each.” By working together to describe individual cases, the medical profession developed an extensive library of standardized case notes and other mechanisms for communicating results. These exchanges paved the way for the advances of bacteriology, immunology, and surgery, and later on, the dramatic mortality declines that are the emblem of development.

Such a “clinical” approach has great promise for all public goods and services—a fact that has not escaped practitioners. Disciplines such as education, disaster risk management, and police services have all begun to develop systematic, evidence-based approaches to the collaborative improvement of outcomes.

To fulfill their public trust, development agencies must help governments and citizens understand not just how much has been spent, but also what has been paid for. Where outcomes are inadequate in the public sector, we must collaborate on the development of better solutions. A global science of delivery offers the most promising way to achieve our common goal: reducing poverty and increasing prosperity for all members of the human community.

Editor's Note: This collection of articles is part of “The Art and Science of Delivery,” an anthology of essays published by McKinsey & Company in honor of the 10th Anniversary of the Skoll World Forum. It is the most recent installment of McKinsey's ongoing series, Voices on Society, which convenes leading thinkers on social topics. (Copyright (c) 2013 McKinsey & Company. All rights reserved. Reprinted by permission)