David Byrne is Emeritus Professor of Sociology at Durham University, UK. He has written on issues of inequality, methodology, and the complexity frame of reference. Books include Social Exclusion (2005), Applying Social Science (2011), Complexity Theory and the Social Sciences – The State of the Art (with Callaghan, 2014), and Paying for the Welfare State in the 21st Century (with Ruane, 2017).