Written in 1999 as many building societies were converting from mutual ownership to shareholder organisation this report is a defence of the mutual principle in organisations. The report book – the first comprehensive review of Britain’s mutual ‘sector’ – shows that mutuality is far from extinct and argues that mutuals could play a far bigger role in the twenty-first century economy. It shows that the mutual sector is far larger, more diverse and innovative than many people realise. Mutuals and co-operatives provide a significant share of the services we rely on most: childcare, insurance, food, community safety, health care, education, social housing and environmental improvement. The report highlights the factors that make mutual enterprises more effective and innovative and the barriers to their success. It sets out a programme for a radical ‘mutualisation’ of services in the UK. Mutuality was a ‘big idea’ in the last century; it can be again in the next, offering a way to combine economic dynamism with social responsibility and community spirit.