Physical Work Intensity and the Split Workday: Theory and Evidence from Spain

This study uses a job-design model and the 2002–2003 Spanish Time Use Survey to explore the existence of a previously overlooked relationship between physical work intensity and the split workday. The theoretical model developed predicts that the incidence of working split shifts may increase with physical work intensity if and only if the degree of recovery allowed by the mid-workday break is directly proportional to the physical load of the work done. Occupation-specific estimates of energy expenditure are constructed for Spain which permit investigating empirically the relationship between physical work intensity and the split workday.