Building capability by delivering results: Putting problem-driven iterative adaptation (PDIA) principles in practice’

International agencies have done well at helping countries with two broad types of problems.1 On purely logistical problems, where the problem is predominantly the expansion of a known technology and an organisation’s agents can follow a script, the world has seen stunning progress – such as the expansion of schooling or immunising children. Similarly, if the problems require adopting policies that are light on implementation – non transactionintensive policies where local discretion is not required – there has also been massive progress: witness improvements in controlling inflation through stronger central banks. However, the global community has been far less proficient at addressing non-simple, non-technical problems that are implementation intensive – such as reducing corruption in procurement, providing dispute resolution, ensuring student learning, and administering land and natural resources.