Inherent in this phrase is that it is something positive, and that needs to be retained in the translation, I think. How should I translate "affirmative action"?
The expression affirmative action comes from Executive Order 10925, signed by US President Kennedy in 1961:
The contractor will take affirmative action to ensure that applicants are employed, and that employees are treated during employment, without regard to their race, creed, color, or national origin. Such action shall include, but not be limited to, the following: employment, upgrading, demotion or transfer; recruitment or recruitment advertising; layoff or termination; rates of pay or other forms of compensation; and selection for training, including apprenticeship.
As you can see, it is very vague. I would recommend kontraŭdiskriminacia agado (action) or kontraŭdiskriminacia regularo (policy). The purpose is to create a general environment of maldiskriminacio.
It has been translated by others as pozitiva diskriminacio but that looks somewhat distortive to me.