nature of the contexts in which that project will operate.<sup>48</sup> Table 7 summarizes the need for a variety of research approaches to answer priority research questions on CDD.

Studies of implementation processes, and how projects are interacting with local contexts, are also useful during the project’s life. To an extent, World Bank supervision missions aim to play this role, identifying issues and problems that can be addressed. Yet understanding these issues requires more in-depth, usually qualitatively focused, studies that set out hypotheses and systematically test them across a range of contexts. While studies may include non-project ‘control’ sites, the focus is less on identifying impact per se but instead more on teasing out whether or not the assumptions that underpin projects’ theories of change hold up, and if so (or if not) why. Such learning can be useful for operational course adjustments but can also contribute to broader theories on the different ways in which projects affected communities, and why.

# 5. Conclusion

Given the size and scope of CDD investments, and its popularity among governments as a development tool, it is imperative to interrogate CDD’s impacts and ensure best practices are integrated into current and future projects. The World Bank alone supports over 350 CDD or CLD projects in 98 countries with approximately USD 45.2 billion.<sup>49</sup> While there are many other popular development tools, governments often turn to CDD to address overlapping development challenges in difficult environments. As governments have increasingly adopted the CDD approach, often with World Bank financing, the approach has evolved to meet new challenges and opportunities, resulting in projects that include components on devolved financing, household cash transfers, local economic development, climate mitigation and adaptation, and inclusion.

This paper calls for a revitalized learning agenda on CDD that focuses on the _conditions under which_ CDD can work and the _design and implementation choices_ that will make CDD most effective within a given context. CDD approaches have a strong record of improving basic services and in some cases also improving economic welfare, participation, and conflict-mediation outcomes. Even as they explicitly harness existing (or establish new forms of) social institutions, however, it is less clear that CDD projects discernably expand social networks and decisively shift pro-social norms – and indeed whether it is desirable that they should singularly expect to be able to do so in such relatively short timeframes. More importantly, many key questions remain unanswered, especially on how variation in project design, implementation modalities, and interactions with contextual factors affect CDD outcomes. Although practitioners often hold tacit knowledge on these factors and incorporate that knowledge into the design and management of their projects, it is important to validate, expand on, and document this knowledge.

We identify gaps in the evidence on CDD and outline a research agenda to build knowledge on CDD’s impacts across four outcome categories, based on three sources of variation. We focus on four outcomes tied to social sustainability – cohesion, inclusion, resilience, and process legitimacy – because social

> 48 Such in-depth analysis is rare. One good example was the Local Level Institutions study in Indonesia that helped shape the design of the _Kecamatan Development Project_ and enabled long-term assessments to be made of social change in everyday village life. See Dharmawan, Jellema, and Wetterberg (2013). A key finding from this study was that conclusions reached after the first round of research were not always supported by research in the second round, raising the obvious specter of whether strident claims and counterclaims based on one-time assessments of interventions in any development sector might be upended if a subsequent round of research were to be conducted. 49 As of July 2023, based on CLD portfolio review.

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