Cities increasingly turn to one another for solutions to shared challenges. This introductory chapter makes the case for approaching the adoption of ideas from other cities more deliberately, so that proven solutions can travel faster and deliver results more effectively, while avoiding the cost of developing programmes from scratch. Adopting an idea is not about copying what worked in another place. It involves understanding how an approach works in its original context, assessing whether it can succeed locally, adapting it and putting it into practice. This process is often more complex than it appears, requiring both technical judgement and co-ordination across teams and stakeholders. The chapter then outlines the objectives of the project and presents the methods and evidence that underpin the analysis.
A Toolkit for Adopting Ideas from Other Cities
Abstract
Urban innovation does not always begin with a blank page. It may also begin with curiosity: how did another city solve an issue we are struggling with? Renca, Chile, asked this question when confronting youth wellbeing challenges and found answers in Iceland, adapting a national model into a locally owned municipal youth policy. Thessaloniki, Greece, raised the same question when faced with a housing crisis, working with European counterparts to create a social housing agency despite the absence of a national legal framework. Dar es Salaam, Tanzania, turned outward to rethink waste management, drawing on Accra’s experience and refining it with support from Bloomberg Philanthropies. Anchorage, the United States, followed a similar path, learning from a low-cost rapid housing project from Atlanta to develop a transitional housing solution fit for its unique context. In each case, learning from peers did not produce copies, but context-sensitive programmes answering local challenges while taking advantage of key takeaways shared by other cities.
Systems of multilevel governance have become increasingly complex in recent years, with authority, expertise, and financial resources distributed across supranational, national, regional and local levels. In parallel, non-state actors, including civil society organisations, NGOs, and transnational networks also play an increasingly important role in supporting policy design and implementation through the provision of expertise, co-ordination, and capacity. In this evolving landscape, local governments (regions and cities) play an increasingly important role to address the challenges related to megatrends, especially in sectors such as transport, energy, broadband, education, health or housing. For example, across OECD countries, subnational governments are responsible for 64% of environment and climate-related public investment (OECD, 2019[1]), and 58% of total public investment across OECD countries (OECD, 2025[2]).
From acute housing shortages to mounting environmental pressures, resilience challenges facing transport and utility networks, or demographic crises, cities are places where global challenges concentrate and intersect with local realities (OECD, 2024[3]). City governments around the world are grappling with the urgency to mitigate the local impacts of these shared challenges. Yet, their actions are limited by capacity and financial constraints that are made more acute by crises such as the COVID-19 pandemic, or demographic changes eroding tax bases (OECD, 2024[4]; OECD, 2025[5]; OECD, 2024[3]). This need to develop ambitious policies under constraints forces cities to be creative and efficient: it is increasingly at the local level that the most innovative approaches are being developed (Rosenzweig et al., 2010[6]; OECD, 2024[3]), within the enabling or constraining frameworks set at national level (Pierre, 2017[7]; Barak and Mualam, 2022[8]).
Reflecting the necessity to innovate in the face of constrained resources and urgent timelines, knowledge sharing between cities is a well-entrenched practice. To understand better the idea adoption process, the OECD and Bloomberg Philanthropies conducted a survey (hereafter the OECD/Bloomberg Philanthropies survey). The survey’s goal was to learn from cities who are adopting ideas from others, and was circulated to cities already involved in peer exchanges, through the OECD Champion Mayors for Inclusive Growth Initiative or through their work with Bloomberg Philanthropies. While academic case studies and experiences highlighted through city networks provide insights into individual examples of city-to-city idea adoption, there is more limited systematic evidence on how widespread these practices are, the sectors in which they occur, and how cities perceive their value. The OECD/Bloomberg Philanthropies survey aims to address this gap, by providing a cross-city perspective on the adoption and adaptation of ideas across different local contexts.
First, this survey reveals that cities look to each other for solutions already implemented by others. Almost 8 out of every 10 (79%) responding cities reported having adopted (or attempted to adopt) at least one idea from another city. Among these, nearly half (47%) have adopted or attempted to adopt three or more ideas in the 5 years preceding the survey. Not only is adopting ideas from elsewhere a widespread practice, but it is also seen in a positive light: among the cities that responded to the question1, 68% agreed or strongly agreed that “My city should adopt ideas that have been successfully implemented in other cities”. Only 17% of cities disagreed or strongly disagreed with this statement (Figure 1.2). City size has little influence on the number of adopted ideas: in all size categories, from small urban areas to large metropolitan areas, one in five cities has adopted more than five ideas. In terms of policy sectors, adopting ideas from elsewhere is most common for policies related to the environment (57% of responding cities), urban planning (44%), infrastructure (43%) and transport (38%). These are sectors that often fall within the core competencies of local governments. They are also directly related to pressing challenges such as resilience to natural disasters. Public safety (17%), tourism, and employment (both 13%) ranked among the least common sectors for adopting an idea from another city (Figure 1.1).
Note: N=69.
Source: OECD/Bloomberg Philanthropies Survey.
For the cities consulted as part of this project, learning from peers, may it be by adopting certain programmatic ideas or adapting a full idea to one’s context, is a way to reduce the need to design policies from scratch, limiting costly trial-and-error processes. This result is aligned with past research on idea adoption (Calzada, 2020[9]; Enseñado, 2023[10]). When addressing wicked, i.e. complex and multifaceted, problems building on tested approaches offers potential to lower implementation costs, accelerate delivery and maximise impact. At the same time, these practices strengthen long-term institutional co‑operation between cities, opening channels for mutual learning that benefits both the cities that develop ideas and those that adapt them (OECD, 2023[11]).
While peer learning is widely endorsed by the cities surveyed and idea adoption appears widespread and valued, results from the OECD/Bloomberg Philanthropies survey also reveal that it may be challenging. Among the 79% of cities that reported having adopted (or attempted to adopt) at least one idea from elsewhere, only 42% fully implemented the adopted ideas at the time of the survey. While none abandoned them, 38% only partially adopted the idea, and 20% had not gone beyond running pilots at the time of the survey. This is a significant result: it suggests that inter-city learning rarely takes the form of wholesale replication. Instead, cities tend to adapt selected elements. This may be the result of their efforts to reconfigure these elements within existing institutional architectures and adapt them to local political and administrative conditions. It may also reflect the challenges associated with translating and implementing whole ideas to a new context.
Indeed, past research has shown that transferring policies across jurisdictions is institutionally demanding. The main barriers identified in the literature are not lack of awareness, but limited absorptive capacity (Cohen and Levinthal, 1990[12]; Zahra and George, 2002[13]) that is, the time, skills, staff and organisational bandwidth required to translate external models into local administrative systems (Greenhalgh et al., 2004[14]; Gilardi and Wasserfallen, 2019[15]). Policymakers often struggle to disentangle whether a policy’s success derives from its intrinsic design or from contextual factors that may not be replicable elsewhere (Nicholson-Crotty and Carley, 2016[16]). Even when formally adopted, policies frequently stall during implementation due to procurement constraints, interdepartmental co-ordination challenges, staff turnover, and short political cycles (Fixsen et al., 2005[17]).
Note: N=45.
Source: OECD/Bloomberg Philanthropies Survey.
Peer networks connect cities around the world and digital platforms have broken down geographic barriers to networking (Acuto and Leffel, 2020[18]; Pierre, 2017[7]). These tools have made it easier for cities to share ideas, data, and practical solutions, even when they are not geographically close (UN-Habitat, 2024[19]). While the growing availability of information on good practices helps ideas circulate, learning from elsewhere is also a proactive process pursued by cities striving for greater efficiency, cost-effectiveness, and evidence-based decision making. According to the OECD/Bloomberg Philanthropies survey, the main reasons for adopting ideas from elsewhere included benefiting from the knowledge developed by other cities (75% of responding cities), ensuring economic efficiency (66%), and strategically aligning with high-potential programmes (62%) (Figure 1.3).
Note: N=69.
Source: OECD/Bloomberg Philanthropies Survey.
Cities adopting ideas from elsewhere is not a new phenomenon. It has been extensively studied in the academic literature under a range of concepts that seek to explain how policies, practices and knowledge circulate across jurisdictions. The concept of “policy transfer”, prominently defined by Dolowitz and Marsh (2000[20]), describes how “knowledge about policies, administrative arrangements, institutions and ideas in one political system (past or present) is used in the development of policies, administrative arrangements, institutions and ideas in another political system”. The terminology has also expanded to terms such as “policy diffusion”, “policy dissemination”, “policy convergence”, “knowledge sharing”, “knowledge transfer” and “lesson-drawing”, which tend to be used interchangeably (Bakker et al., 2024[21]; Marsden and Stead, 2011[22]). Both the objects of inspiration (ranging from full policies to broad insights) and the modes of learning they enable (whether through transfer, convergence, or simple lesson-drawing) are highly diverse.
Which insights travel between cities?
Dolowitz and Marsh (1996[23]) identify seven main objects of transfer: i) policy goals, structure, and content, ii) policy instruments, iii) administrative techniques, iv) institutions, v) ideology, vi) attitudes, ideas, and concepts and vii) negative lessons. Cities learn from one another constantly, including by exploring the application of integrated approaches to service delivery and public problem-solving to their own context. These ideas often combine multiple elements, including how a problem is defined, how services are designed and delivered, how residents and frontline staff are engaged, and how solutions are tested, refined, and scaled. This toolkit uses the term “idea” to refer to coherent approaches to addressing public problems. To embrace an idea, cities need to adapt it to their local context, governance and policy objectives. This may imply unpacking and repackaging the idea, blending it with local principles.
A useful example of idea adoption is the CAHOOTS (Crisis Assistance Helping Out On The Streets) crisis-response model, which originated in Eugene, Oregon (the United States) and was adopted by other cities across the United States. CAHOOTS is a specific, institutional service model that involves dispatching mobile crises teams, typically composed of a health professional and a social worker, through the 911 system instead of the police in response to non-violent emergencies (e.g. mental health, substance abuse or homelessness). Several US cities have thought to explicitly adopt CAHOOTS by developing local programmes that replicate its core organisational features. Adopting this approach in another city or country may involve blending the idea with existing local emergency call response systems. It may imply involving other stakeholders depending on the structure of social work and the local health sector. The governance of this programme as well as its funding may be organised in entirely different ways. Nevertheless, what defines these cases as adoptions is the deliberate uptake of a recognisable and bounded programme, with identifiable core components.
This example helps clarify what falls outside the scope of idea adoption. For instance, while 311 non-emergency call systems, which allow residents to request assistance without using emergency lines, similarly aim to route issues to the most appropriate service provider, they do not constitute CAHOOTS adoption. Rather than replicating a specific programme with defined operational protocols and staffing models, they reflect a broader administrative logic of service differentiation. Such cases are better understood as parallel or convergent innovations, or at most as loosely inspired by similar problem framings, rather than instances of direct idea adoption.
Adopting rather than transferring
In this toolkit, the implementation of ideas from other cities is referred to as “adoption” rather than “transfer”, “sharing”, “dissemination” or “replication”. Indeed, these terms tend to convey the idea of a copy-paste exercise, while “sharing” or “dissemination” tends to understate the amount of work necessary to re-root an idea into a new political, institutional, legal, socio-economic and geographic context. By contrast, “adopting” an idea from elsewhere implies a proactive process of unpacking narratives to reveal an underlying principle, assessing to evaluate compatibility with the local context and suitability to local issues, adapting using local expertise and skills, repackaging to meet the needs of stakeholders and finally, implementing. All in all, adoption refers to the process of learning from another government’s idea and making it one’s own while retaining core principles.
The process of idea adoption
Understanding how ideas travel, and how they evolve as they travel, is key to helping cities gain as much value as possible from peer learning practices. Past research shows that learning from elsewhere does not follow a single or uniform path. Ideas may be exchanged directly between actors, or they may spread more gradually through broader processes of policy diffusion, in which an innovation or practice gains traction through repeated uptake over time (Bakker et al., 2024[21]). Urban knowledge transfer is rarely a simple, one-way process. Some models describe it as a linear transmission (Del Giudice, Della Peruta and Maggioni, 2013[24]) from a more experienced “sender” to a less experienced “receiver”. Enseñado (2023) identifies four theoretical stages. First, exploration, where cities engage with peers to exchange knowledge and practices. Second, acquisition, when participants process and assess the relevance of this information. Third, utilisation, as the acquired knowledge is applied at the organisational level. Finally, internalisation, where new ideas are institutionalised into lasting policy frameworks (Enseñado, 2023[10]).
While these theoretical stages are helpful to engage with the idea adoption process, Enseñado stresses that actual practices tend to be more iterative and dynamic. Insights from local governments consulted in this study show that cities may first start designing a response to a problem from scratch, then be inspired by ideas from elsewhere at the implementation stage (e.g. in finding innovative ways to gather resources). They can also discover an idea through engagement with a network before the agenda is set to solve the specific issue this idea would address. Different ideas may also shape the policy process without being adopted. Finally, factors such as cultural differences, institutional capacities, and local politics influence the way knowledge from elsewhere is translated into action (Bakker et al., 2024[21]).
Overall, the concept of idea adoption used in this toolkit highlights that learning from elsewhere operates along a spectrum. At one end lies full adoption, where an idea is adapted and implemented locally with only minor adjustments. At the other end is looser, more partial adoption: even when an external idea becomes unrecognisable in a city’s policy, initiative, or programme, its underlying principles, objectives, or institutional arrangements may still have inspired local authorities seeking effective solutions to local challenges.
Cities consulted as part of this study widely engage with ideas from elsewhere and express a big appetite for learning from peers. Yet, insights from the OECD/Bloomberg Philanthropies survey as well as from interviews with cities, reveal that adoption efforts remain largely ad hoc rather than strategically planned and integrated in regular policymaking activities. There are many ways local governments learn from peers, some pro-active (e.g. engaging with networks, participating in idea exchanges) and others, unconscious and embedded into regular policymaking (e.g. benchmarking ideas from other cities to find inspiration when working on developing a new programme from scratch). Learning from peers is already a common and multifaceted practice that requires more than learning about the ideas to actively assess and adapt them. As such, its benefits could be significantly enhanced were cities to engage in a more strategic approach to peer learning.
Supporting the adoption of ideas from elsewhere requires understanding why cities choose to engage with certain ideas, the conditions that facilitate or hinder their adoption, and the practical challenges involved in adapting and sustaining them over time. While academic interest in knowledge-sharing and policy learning has grown rapidly over the past decade (Bakker et al., 2024[21]), existing research offers limited insight into how cities engage with the successes of their peers in practice, and its findings are not always readily applicable to local policymaking (Glaser et al., 2021[25]). Rather than proposing a comprehensive or systematic model, this toolkit draws on experiences, challenges and successes shared by a variety of local governments to provide a snapshot of approaches that cities are currently using.
Recognising the multiple potential paths towards successful idea adoption, it does not aim to highlight best practices as authoritative examples. Instead, it highlights the factors that appear to enable or constrain their adoption, showcases a variety of approaches that have led to success (or learning) in cities of different sizes, contexts, resources, and priorities, and offers practical reflections to help cities engage more effectively with ideas developed elsewhere. While some of the approaches highlighted are innovative, others draw on regular policymaking practices (e.g. stakeholder consultation) that can be leveraged to support the adoption and adaptation of ideas from elsewhere.
This toolkit is based on four main sources of evidence:
The OECD/Bloomberg Philanthropies survey: a survey of 76 cities across 43 countries, gathering data about idea adoption practices, the reasons behind these practices, and the adoption process itself.
Case-study interviews conducted with 16 local governments (Anchorage, the United States; Colombo, Sri Lanka; Dar es Salaam, Tanzania; Kampala, Uganda; Lagos, Nigeria; Liverpool City Region, the United Kingdom; Melbourne, Australia; Okayama, Japan; Renca, Chile; Rio, Brazil; Rotterdam, the Netherlands; State of Jalisco, Mexico; Tallinn, Estonia; The Hague, the Netherlands; Thessaloniki’s Major Development Agency, Greece; Vienna, Austria). These cases were selected to reflect the variety of experiences in idea adoption. They ensure a degree of geographical diversity to fill a gap in the literature on peer learning among cities, which has tended to focus on large cities in Europe and North America (Haupt et al., 2019[26]). These case studies are not meant to single out “best practices”, but rather to illustrate different ways to implement the actions included in the toolkit.
An in-person high-level workshop to explore, conceptually and practically, how and why cities are adopting ideas from elsewhere. Participants were encouraged to share both successes and failures, with the recognition that learning from what has not worked is just as valuable as celebrating what has.
Two webinars:
A first webinar to validate and complement survey findings with qualitative insights from cities, address evidence gaps not captured in the survey and identify strong case study candidates.
A second webinar present actions from the toolkit and receive feedback on their relevance and usability from local government representatives.
Users can engage with any section of this toolkit independently, depending on their priorities and stage of idea adoption. The following paragraphs provide guidance on how to navigate the report.
If you are focusing on a specific step of the idea adoption process
Each step is explored in a dedicated chapter:
Step 1 (Building your city’s capacity to learn from others) focuses on key enablers such as leadership, culture, governance, and networks that enable cities to borrow ideas from elsewhere.
Step 2 (Evaluating ideas for local fit) provides guidance on determining whether the borrowed idea is suitable for a different city, i.e. assessing its relevance, feasibility, and potential impact in the local context.
Step 3 (Adapting and implementing ideas) supports cities in translating ideas into local impact, including adapting the idea to the local context, testing it, reshaping it with the target group, and securing resources.
Each chapter includes a list of practical actions. The actions are practical, illustrated with city examples, and designed to be used flexibly. They are not exhaustive or prescriptive, and can be applied independently to support reflection, experimentation, and implementation.
If you are looking for the latest research on sharing ideas between cities and evidence to support idea adoption
Each chapter opens with a short “Why it matters” section that summarises relevant evidence from academic research, expert input and the OECD/Bloomberg Philanthropies survey. These sections help readers anticipate trade-offs and common pitfalls when deciding whether and how to adopt ideas from elsewhere and can also be used to build internal and external support for taking them onboard.
If you are looking for city examples
Most of the actions of the three steps are illustrated by concrete practices drawn from cities across different contexts. These examples illustrate how actions have been implemented in practice, outlining key features of the idea adoption process and lessons learned. They are intended to inspire and inform idea adoption, rather than serve as models to be replicated.
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← 1. Not all questions were mandatory. This choice was made to limit attrition. The average response rate by question was 60 cities. The minimum response rate (43) was reached for the question “Please indicate which of the following features of the idea was maintained or changed.”