The Equality Trust is a UK registered charity that campaigns against economic and social inequality.

[2] The Trust campaigns for governments to take action on inequality, starting in the 2010 and 2015 UK general elections.

[5] Wilkinson and Pickett published a second book, The Inner Level: How More Equal Societies Reduce Stress, Restore Sanity and Improve Everybody's Wellbeing in 2018.

They argued inequalities across society cost at least £106.2bn yearly compared to the average OECD country's level of equality, making the UK's top 1% the most expensive in Europe.

[10] The Equality Trust released an update to the original Spirit Level book, written with Wilkinson and Pickett, that provided updates to the original research in The Spirit Level and expanded on its arguments with new research into inequality's impact on climate, democracy and society.