In employment positive discrimination is the policy that if in case of a job vacancy there are two or more equally qualified applicants, the job will be awarded to those applicant who belongs to a disadvantaged group (such as ethnic minorities or women). At first sight positive discrimination seems to be attractive, but positive discrimination, as well the related concept of quota, has several issues.
Positive discrimination necessarily also implied negative discrimination, of those who are not a member of a disadvantaged group. If an employer has a preference (whether or not as result of government policy) for underprivileged applicants, than applicants of more advantaged backgrounds will have a lesser chance of getting a job. Though positive discrimination and quotas might be a good temporary measure to correct past injustices, if such policies are, however, pursued to long it will backfire.
A second concern of these, well-intended, policies is that they might actually reinforce those social attitudes which caused negative discrimination of certain groups. When there is in case of (more or less) equal qualifications, a preference for (say) either women or ethnic minorities, some people might think that one has received his/her job only because of his/her background and not because of his or her qualifications. Such attitudes, however unjust they might be, could be disastrous for an employee of a disadvantaged group.
If neither positive discrimination nor quotas might have adverse consequences, are there alternatives? Instead of positive discrimination, we could use random selection (a.k.a. lottery) as a procedure of rewarding a job in case of multiple more or less equally qualified applicants. This method is fair, in that it gives all qualified applicants an equal chance to get the job regardless of their background.