Those involved in mental as opposed to physical effort or…

““Those involved in mental as opposed to physical effort or who carry the responsibilities of management are presumed to require a higher payment for their submission to the purposes of organization than those who render only physical or manual service, however adept or talented that may be. This is because there is profound difference in the nature and extent of the submission that is made. The person on the shop floor or its equivalent gives more or less diligent and deft physical effort for a specified number of hours a day. Beyond that nothing in principle--not thought, certainly not conformity of speech or behavior--is expected. Of the high corporate executive a more complete submission to the purposes of the organization is usually required. He (or she) must speak and also think well of the aims of the enterprise; he may never in public and not wisely in private raise doubt as to the depth and sincerity of his own commitment. Many factors determine his large, often very large, compensation, including the need to pay for the years of preparation, for the considerable intelligence that is requires, for the responsibility that is carried, and for the alleged risks of high position. As a practical matter, his rate of pay is also influenced by the significant and highly convenient role the executive plays in establishing it; much that accrues to the senior corporate executive is in response to his own inspired generosity. But there is also payment for the comprehensive submission of his individual personality to that of the corporation. It is no slight thing to give up one's self and self-expression to the collective personality of one's employer.””

— John Kenneth Galbraith