Employees and proprietors are most often in a transactional relationship with consumers; they produce goods that consumers buy using their income. But this need not be the case. Physicians at a ‘free clinic’ are not paid by their patients but by a government agency, charity, etc. Nevertheless, such employees expect to earn income from their work from some source. But some instances of work go unpaid or uncompensated altogether. Slaves work, as do prisoners in some cases, but their work is often not compensated. So too for those who volunteer for charities or who provide unpaid care work, attending to the needs of children, the aged, or the ill.