Pope John XXIII
Mater et Magistra §70
Mater et Magistra: On Christianity and Social Progress
70 In economically developed countries, relatively unimportant services, and services of doubtful value, frequently carry a disproportionately high rate of remuneration, while the diligent and profitable work of whole classes of honest, hard-working men gets scant reward. Their rate of pay is quite inadequate to meet the basic needs of life. It in no way corresponds to the contribution they make to the good of the community, to the profits of the company for which they work, and to the general national economy.
Source: Mater et Magistra (Vatican.va)