Education, healthcare, social security and housing are the four pillars of the welfare state (Torgersen, 1978). The welfare of those who collectively contribute to a city’s wealth has been of concern to city elders for millennia. The modern welfare state underwent unprecedented expansion in the second half of the 20th century, pursuing with modern ideas, fiscal instruments and social and physical infrastructure, underpinned by unparalleled levels of income. The modern municipal government is now expected to deliver, via tax, land and other revenues, what has, over the millennia, been provided in a much less comprehensive and complete way via private and religious philanthropy. The cities of even the highest income countries are struggling under this noble responsibility, unable now to fund the publicly-subsidised health systems and generous pension schemes that in the post WW2 ‘welfare state revolution’ optimistically heralded a new phase of civilisation. If this is the West’s experience, what of today’s developing countries and countries navigating transitional economies? One thing is for sure: as the latter set their paths towards fair and fit, efficient and equitable futures, they need to learn sober lessons from the experience of the 20th century and plan for sustainable urban welfare systems. Covid-19 will make a huge difference to all these. Not so much because national and city governments will need to plan for pandemics and more virulent and frequent epidemics, but because of the financial legacy of governments’ crisis responses, which are of war-time proportions and will indebt the populations of rich and poor countries alike for several generations.

With the common goal of promoting citizens’ wellbeing, countries around the world have experimented with a variety of mechanisms to fund and deliver social infrastructure to levels of comprehensiveness suitable to their public purse. Urban welfare packages also vary by different priorities and levels of commitment, determined by politico-economic and institutional settings. In China, the equalisation and optimisation of social infrastructure across regions, cities and urban neighbourhoods, has become the next foremost task in tackling the problems of inequalities and uneven development that have accompanied the decades of rapid growth in the post-reform era (Li, He et al., 2020). Building upon the research team’s two decades of studies on urban (re)development, urban poverty, low-income housing, complex self-organising urban systems,  spontaneous social order, and gated communities; and supported by ongoing GRF and NSFC research projects, the SIEW lab brings together multi-disciplinary researchers from Europe, US, Australia, Japan, Mainland China and Hong Kong. Their shared interest is in probing the long lasting and deep seated problems of growth and inequality in three major types of urban social infrastructure, namely housing, healthcare, and education, with an ultimate interest in improving opportunity, equity and wellbeing among urban citizens. Synthesising theories and methodologies from multiple disciplines, the SIEW lab draws on critical urban theories, as well as behavioural economics, political, sociological, psychological and spatial theories about welfare, health, education and housing systems and regimes. SIEW’s specific foci include 1) formal and informal affordable housing development in developing economies; 2) multi-dimensional housing inequalities under financialisation in pandemic-stricken megacities; 3) uneven distribution of high-quality healthcare resources and resultant patient mobility and physician mobility; and 4) emerging forms of neighbourhood order, including for example, gated communities featuring privileged access to education service and exclusive residential environments and the systemic implications for equity in education, housing and urban resilience.