David Lockwood is a sociologist.

His book, The Blackcoated Worker, (1958 & 1989) sought to analyse the changes in the stratification position of the clerical worker by using a framework based on Max Weber

Max Weber

Karl Emil Maximilian "Max" Weber was a German sociologist and political economist who profoundly influenced social theory, social research, and the discipline of sociology itself...

's distinction between market and work situations. Lockwood argued that the class position of any occupation can be most successfully located by distinguishing between the material rewards gained from the market and work situations, and those symbolic rewards deriving from its status situation. His work became a very important contribution to the 'proletarianisation' debate which argued that many white-collar worker

White-collar worker

The term white-collar worker refers to a person who performs professional, managerial, or administrative work, in contrast with a blue-collar worker, whose job requires manual labor...

s were beginning to identify with manual workers by identifying their work situation as having much in common with the proletariat

Proletariat

The proletariat is a term used to identify a lower social class, usually the working class; a member of such a class is proletarian...

.