A Toolkit for Adopting Ideas from Other Cities

Learning from peers has increasingly emerged as a key strategy for cities seeking to address complex and shared challenges, such as affordable housing shortages, climate risks, infrastructure pressures and persistent social inequalities. By adopting existing policies, cities can reduce uncertainty and improve outcomes, compared to developing solutions from scratch.

However, while inter-city learning is widespread, it remains largely informal and rarely results in the full adoption of coherent programmes. According to a survey of 76 cities across 43 countries (hereafter the OECD/Bloomberg Philanthropies survey), 79% of cities report having adopted or attempted to adopt at least one idea from another city, yet only 42% report full implementation. This gap suggests that policy ideas do not travel intact: they are unpacked, interpreted, reassembled and embedded within distinct institutional, political and socio-economic contexts. Adoption today is therefore best understood not as transfer, but as a process of contextualised reinterpretation. At the same time, these partial adoptions also reflect the absence of structured approaches to policy adoption and ad hoc processes that may not allow to fully unlock the benefits of peer learning.

To move from ad hoc to more effective idea adoption, this report offers cities a practical toolkit structured around three key steps of the adoption process: putting in place the conditions that allow cities to learn from others, strengthening how they assess which ideas to pursue, and improving how they adapt and implement borrowed ideas in practice.

First, city governments can put in place the conditions and build the capacities that allow them to consistently learn from and act on ideas from elsewhere. While local governments are often open to external ideas, these efforts frequently depend on ad hoc initiatives rather than structured processes. Limited administrative capacity and financial resources are the most frequently cited barriers, reflecting the everyday realities of local governance rather than exceptional circumstances related to idea adoption. Within this context, successful “adopter cities” are not necessarily those with greater resources, but those that are more deliberate in how they organise learning processes. Political leadership also plays a central role: three-quarters of surveyed cities identify it as the most important enabling factor, particularly in prioritising initiatives and mobilising resources. At the same time, staff capacity, organisational culture, institutional arrangements, and access to city networks shape whether ideas can be identified, explored and developed further. To strengthen their capacity to learn from others, cities can:

• Empower staff to identify and experiment with ideas from elsewhere

• Anchor adoption efforts in existing political and strategic priorities

• Engage with inter-urban networks to access knowledge and support

• Introduce clear processes and assign responsibilities to embed idea adoption in everyday practice so that this work does not rely on individual initiative alone

Second, city governments can strengthen how they assess which external ideas to pursue. Ideas often travel through compelling narratives that highlight success and innovation, but these narratives rarely provide sufficient information to inform effective assessment. Evaluating local fit requires moving beyond these accounts to examine the causal mechanisms and contextual factors underpinning an initiative. This includes understanding how an idea was implemented, by whom, at what cost, and with what outcomes, as well as assessing whether similar results can be expected in a different institutional, social or political context, and whether adaptations may be needed to fit local context. While the cities surveyed report relying on data, piloting and cost-benefit analysis, assessment processes are often informal and embedded within broader policy development. Strengthening these processes therefore involves making them more deliberate by:

• Gathering the right evidence to unpack success stories

• Assessing compatibility with local conditions, including priorities, cultural and geographic context, governance arrangements, institutional capacity and resource constraints

• Testing local relevance with target groups before committing to implementation

• Where necessary, working with national governments to address structural barriers (e.g. legal framework, availability of data) and strengthen local capacity to assess ideas.

Third, cities can reinforce their capacity to adapt and implement ideas borrowed from elsewhere in ways that fit their local context, as identified in the second step. Findings highlight that this process is neither linear nor purely technical, but iterative and politically embedded. More than 90% of surveyed cities adapt ideas to local conditions, adjusting design, scale, funding models or governance arrangements, while attempting to retain the core features of the idea. Challenges related to funding, capacity or political support frequently require cities to revisit earlier design choices, making adaptation and implementation closely intertwined. Insufficient adaptation, weak institutionalisation or unstable political support can significantly undermine outcomes. Cities that anticipate these constraints and integrate testing, stakeholder engagement and iterative adjustment into adaptation and implementation processes are more likely to sustain results over time. In practice, this requires:

• Building and maintaining political leadership and administrative ownership to adapt and implement the borrowed idea

• Securing adequate internal and external financial resources for borrowed ideas

• Co-designing adaptation and implementation with target groups

• Adapting borrowed ideas to local mandates and revisiting governance when needed

• Testing and piloting solutions before scaling

• Documenting and sharing implementation experience, contributing to broader learning across cities.