The authors analyse change in employment levels and in the task content of occupations, both within occupations (i.e. at the intensive margin) and between occupations (i.e. at the extensive margin) in the United Kingdom over the period 1997-2006 using data from the national Skills Survey, which has comparable within-occupation task data for three waves: 1997, 2001 and 2006. They find that within-occupation task content changed significantly, and that the magnitude of change was similar to that found at the extensive margin. Their econometric results suggest that these intensive-margin shifts can be explained by technological improvements but not by offshoring.