Too many workers leave the labour market permanently due to health problems, and yet too many people with a disabling condition are denied the opportunity to work. This second report in the OECD series Sickness, Disability and Work explores the possible factors behind this paradox. It looks specifically at the cases of Australia, Luxembourg, Spain and the United Kingdom, and highlights the roles of institutions and policies. A range of reform recommendations is put forward to deal with specific challenges facing the four countries.