David Lockwood (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'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 workers were beginning to identify with manual workers by identifying their work situation as having much in common with the proletariat. Lockwood later moved into the field of war studies, a change of tack that was viewed as surprising and controversial by some of his peers. In spite of this Lockwood has maintained his high standards of academic achievement and is generally considered an indispensible asset of Salford University, where he is now a professor.