GCRF Accountability for Informal Urban Equity Hub More than half of humanity currently lives in urban areas and 68% are projected to do so by 2050. One in three urban dewllers, and an estimated 881 million people in Low and Middle-Income Countries (LMICs) now live in informal settlements, colloquially known as 'slums', where they have inadequate, insecure housing and limited services. These settlements are often the only option for people working in the informal sector, and existing evidence shows that residents are often highly resourceful, resilient and innovative in navigating the problems they face daily.  However, they also face challenges that appear intractable:  multiple health and well-being risks and vulnerabilities, related to an unhealthy environment, insecurity and social marginalisation.  Informal urban settlements are rapidly changing, with in and out-migration and shifts in social norms, as well as being economically and socially unequal.  Failures to provide services, infrastructure and mechanisms for redress by national and local governments are often linked to the presence of multiple actors and organisations including non-governmental, private and criminal organisations. These conditions can act as an incubator for various forms of violence (e.g. political and gender-based), which threaten well-being.    Our Hub will work with the most marginalised dwellers in informal urban settlements, including through federations of 'Slum/ Shack Dwellers', linked to Hub partner SDI. We will support them in identifying their priorities, making their conditions visible to key service providers related to health (both governmental and non-governmental) across a range of sectors, and working with identified allies amongst these actors to develop better mechanisms for accountability and more responsive services.  We will test this approach to addressing this intractable challenge, and pilot the priority interventions developed.  Many conventional research methods and routine information systems are ill-suited to these complex and rapidly changing contexts and are not sufficiently linked to action. We will use innovative participatory methods, including analysis of data collected by informal urban dwellers themselves, to gain a deep understanding of health risks, vulnerabilities, and priorities and service access barriers. We will bring insights from a range of disciplines including social and political sciences and epidemiology to develop innovative metrics that can better reflect these realities and inform policy and practice development and evaluation.  Learning and data from these innovative approaches and methodologies will be brought together to form a tested set of methodologies that identify promising mechanisms for improving accountability and service responsiveness to promote health and well-being for the most marginalised. We will communicate the new concepts, evidence and methodologies to national, regional and global governmental and non-governmental organisations through our networks and partnerships to maximise the potential for improved policies, strategies and services.   Our Hub is uniquely placed to realise our vision. We bring together partners with long standing relationships, and develop new collaborations that add value in terms of expertise and networks.  IDS and University of Glasgow bring core strengths in participation and urban governance; epidemiology and inter-sectoral action respectively. LMIC partner institutions have strong national, regional and global influence and reach, including with informal urban dwellers (e.g. SDI and APHRC), with national and international non-governmental organisations (e.g. LVCT Health, BRAC ) and with national governments (e.g. COMAHS, SLURC, The George Institute).  LSTM has an outstanding track record in leading successful multi-partner collaboration for health impact. We will collectively build interdisciplinary capacities across the Hub and use this learning to benefit the next generation of researchers. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.