This week the Moral Maze asks "are mixed communities a moral good?" With the government rolling out its benefits cap and a study claiming that high rents mean a third of Britain is effectively off-limits to lower-income working families, some campaigners are arguing that the less well-off are the victims of social cleansing. It's argued the lack of affordable housing means that large parts of the country, especially London, are being turned in to homogenised gated communities reserved for the well off and where the poor are welcome to work, but not to live. Does that really matter? Should we let the free market solve these problems, or use planning laws to make sure property developers build social housing alongside more expensive homes? Should the tax and benefits system be used not just to make sure that people have a roof over their heads, but also to shape the social make up of our communities and nation? Are pluralist, socially diverse communities inherently better - a sign that we're a healthier, tolerant, more democratic society? Or have we for too long been beguiled by the dream of a melting pot? And not only is it human nature to want to live in a community with people who have the same kind of background, values and aspirations, but those communities also create virtues such as neighbourliness, trust and social solidarity. By trying to create more diverse and integrated communities are we undermining the strong social ties that create truly cohesive communities? Combative, provocative and engaging debate chaired by Michael Buerk with Michael Portillo, Anne McElvoy, Giles Fraser and Matthew Taylor. Witnesses: David Goodhart - Director of think tank Demos, Professor Jane Wills - Department of Geography and The City Centre, Queen Mary University of London, Philip Booth - Editorial and Programme Director at the Institute of Economic Affairs and Ruth Davison - Director of Policy at National Housing Federation.