Response options: Not asked, Not applicable, No answer, Manager 10 or more employees, Manager less than 10 employees, Professional, Supervisor, Non-manual worker, Foreman, Skilled, Semi-skilled, Unskilled, Farmer, Agricultural worker, Armed forces
Response options: First version, Revision June 2011, Revision October 2011 (IDEA), Revision May 2012 (Big five), Revision May 2012 + Sylatech MENA module
