Is the Diversity Index Fit for Purpose in Studies of Life Course Specialization?

• In Event: Perspectives on Life Course and Genetic Issues in Crime and Substance Use

Abstract

The diversity index is a common method of measuring specialization in lifecourse studies. Recent work, for example, has used this index to investigate the relationship between specialization and age of offending, where specialization is measured over short time periods. However, as frequency of offending tends to decline with age, the results of such studies are critically dependent on the index being invariant to frequency of offending. This talk presents evidence that the index is indeed related to frequency of offending. It uses some simple simulated datasets with a known, constant level of specialization but varying frequency of offending, and shows a strong increase in the index with frequency. The implications of these results are discussed and some solutions to this problem are presented.

Authors

• Brian Francis, Lancaster University, UK

• Leslie Humphreys, Lancaster University, UK