Average partner incomes in the major management consultancy firms are high compared with the average incomes of senior people in some (but not all) other occupations. This appears to be explained in part by the high level of expertise that is needed to perform these roles, and also the high impact of their work on their clients' organisations. Nevertheless, other occupations with comparable requirements for expertise, and comparable impact, appear to attract somewhat lower average incomes, and I have not been able to identify any research that discusses the reasons for this relativity. Are you aware of any research publications please that have discussed this issue?