Of course, in some cases, the legal or "de facto" requirement for a degree helps to protect society, as in the case of the requirement for an M.D. degree to practise medicine, or a B.Eng. degree to become a civil engineer and build bridges and dams. However, a number of white collar jobs require degrees that are not explicitly connected to the job requirements. Some banks require applicants for their financial advisor positions to have a degree in economics, even though the job, which is based around selling stocks, bonds, and mutual funds, does not require training in economics. Similarly, many state and federal governments in North America require policy analysts to have a university degree in any field to be hired, even though the writing and research skills needed to be a policy analyst could be gained by experience.
Employers that require credentials that are not explicitly related to the work tasks may be using the possession of the university degree as a screening mechanism, as the completion of a degree may serve as a proxy for measuring traits that are desirable in the workplace (e.g., finishing tasks, learning new skills, following instructions). Some Marxist critics argue that these requirements for credentials not needed for the job are a social class screen, to ensure that the candidates selected for a job are bona fide members of the middle class. By requiring a university degree for entry level office jobs, employers are in effect screening out candidates from lower socioeconomic backgrounds, as these individuals are much less likely to attend and complete a degree, due to the many barriers that university attendance poses for them (financial, social, etc.). This screening approach may be unfair for competent, experienced people without university degrees; a skilled writer and editor with decades of experience may be unable to even get an interview as an entry-level policy analyst in the federal government.
Some professions rely to higher degree on credintials. In many cases, the granting of professional licenses has been institutionalized, with the power to grant licenses given to self-regulatory bodies, such as medical associations or law societies. Laws may dictate the need for a credential by a requirement is set at the state, provincial, or federal level (e.g., the requirement that a civil engineer possess a B.Eng. degree). Credentials acquired in one country (or region) by a worker are often not fully recognized in other countries or even in other states or provinces. In Canada, a teaching certificate or bar admission (for a lawyer) is only valid in the province in which it is granted; if a worker moves to another province, they have to write the certification exams in the new province, which can be costly and time-consuming.
Immigrants with foreign credentials often find that their degrees are not recognized in their new country. In Canada and the US, immigrants with credentials from non-Western countries may have to complete a number of additional courses or follow a costly or lengthy re-certification process. Foreign medical doctors, even those with decades of experience, may have to enrol in a North American medical school and re-do their internship. Foreign tradespeople such as electricians and plumbers may have to start again in the apprenticing system. Faced with these hurdles, many immigrants find that they have to work in a field other than the one that they are trained in, a situation called underemployment. An Egyptian-trained surgeon may end up driving a cab in Canada, and a British-trained Zimbabwean engineer may end up delivering pizza in the US.
Opposition to credentialism is a tenet of the unschooling movement.
There's also negative credentialism, in which an arrest record, restraining order, dishonorable military discharge, bad credit rating, medical diagnosis, foreign birth, or other formal negative credential, is used to discriminate against a person, even if the negative credential is mistaken, obsolete, irrelevant, or actually belongs to someone else with a similar name.