reform—such as those in Lagos and Edo, Nigeria—have combined parallel investments in enforcement, facilitation and trust.<sup>156</sup> However, while the connections between enforcement, facilitation and trust are increasingly recognized, existing work has struggled to translate this broad insight into concrete strategies for strengthening reform. While individual research findings have pointed toward specific types of interventions that have been successful in specific contexts, a broader framework is needed in order to identify appropriate reform strategies that are likely to work in particular contexts. This would take into account the variations in starting points, objectives, and constraints. Such strategies need to be able not only to identify technical challenges and barriers to reform, but to analyze political barriers, to identify binding constraints on reform, and to adopt targeted strategies for building trust – and strengthening fiscal contracts – as part of holistic reform strategies.

International organizations have recently made considerable progress in assessing the policy and administrative barriers to improved performance. Tools such as TADAT and DIAMOND offer a nuanced understanding of what is not working in relation to various aspects of tax enforcement, while also offering a snapshot of some aspects of facilitation and taxpayer outreach. However, identifying what is not working is only the first step to identifying the appropriate target for reform. The latter requires understanding where reform is technically and politically feasible – and which areas of “dysfunction” are the most binding constraints on overall performance. For example, in the context of sharply limited human resources, broad-based capacity building for international taxation may face technical limits – and efforts at highly targeted enforcement, or policy simplification, may offer greater payoffs.

Reformers may consider an interconnected – but not necessarily linear – set of questions in guiding reform design. These are, of course, likely to vary by country, but offer a sense of how reform programs that are tailored to local contexts, and which combine enforcement, facilitation and trust, may be developed. First, what are the central objectives of reform? Second, what are the key political barriers to reform? Third, what are the binding constraints on reform? Fourth, how can investments in enforcement, facilitation and trust best be combined? What follows considers each element of potential reform strategies in turn.

_Social Desirability: What are the central objectives of reform?_ The starting point for any reform is a clear understanding of what the reform aims to achieve, and what broad strategies may contribute to that goal. Central to most reform efforts is a desire to increase revenue collection. However, reform is equally likely to be motivated, in varying degrees, by desires to increase economic efficiency, expand equity, improve trust in government and strengthen the fiscal contract. These latter objectives are critical to thinking about the development goals of reform. Expanded taxation is only socially beneficial if it translates into reciprocal benefits for taxpayers, while the extent of those social benefits will be much larger where tax and fiscal systems are fair, equitable and redistributive.

> 156 Cheeseman, N., & de Gramont, D. (2017). Managing a mega-city: Learning the lessons from Lagos. _Oxford Review of Economic Policy_ , 33 (3):457-477; Porter, D. & Watts, M. (2017) Righting the resource curse: Institutional politics and state capabilities in Edo State, Nigeria. _The Journal of Development Studies_ , 53:2, 249-263.

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