Pope John XXIII
Mater et Magistra §71
Mater et Magistra: On Christianity and Social Progress
71 We therefore consider it Our duty to reaffirm that the remuneration of work is not something that can be left to the laws of the marketplace; nor should it be a decision left to the will of the more powerful. It must be determined in accordance with justice and equity; which means that workers must be paid a wage which allows them to live a truly human life and to fulfill their family obligations in a worthy manner. Other factors too enter into the assessment of a just wage: namely, the effective contribution which each individual makes to the economic effort, the financial state of the company for which he works, the requirements of the general good of the particular country—having regard especially to the repercussions on the overall employment of the working force in the country as a whole—and finally the requirements of the common good of the universal family of nations of every kind, both large and small.
Source: Mater et Magistra (Vatican.va)