Multiple Jobs and Inequality in Earnings

This paper shows that individual and structural factors which determine professors' salaries also influence, in various degrees, the accumulation of earnings from additional sources. As a result, those who receive greater rewards from their main work role are likely to have proportionately higher supplementary incomes. Thus, expanding occupational role-sets increase the inequality in economic rewards in the academic system. It is proposed that the relative effect of each of the salary determinants on extra earnings depends on their ability to generate, directly or indirectly, extra earning opportunities.
The examined factors are professorial rank, research productivity, departmental prestige and the length of academic experience. Professorial rank has been shown as the main determinant of institutional salary level, whereas research productivity is the most crucial factor in generating extra earning opportunities. It is likely that the importance of the latter, in our case, is mainly indirect in that it generates critical intervening resources such as professional reputation, visibility in the academic system and communication network.