McDonnell Douglas Proof Model
At the first stage, the employee must make out what’s called a “prima facie” case. Prima facie is simply Latin legalese for “at first look.” A prima facie case of age discrimination is made out if an employee can show that at first look, his termination or other adverse action was “compatible” with age discrimination. For example, an employee might show that he was laid off while younger workers were retained, or that after the layoff he was replaced in his position by a younger less experienced worker.
Once the employee has made a “prima facie” case, in the second stage, it is up to the employer to give its excuse by providing a nondiscriminatory reason for the layoff. Because older employees often have higher salaries by virtue of their seniority, a frequently used excuse by employers is that an employee was laid off because of his higher salary and not because of his age.
In the third and final stage, the employee must prove that the employer’s excuse is a “pretext” — that employer is lying about the true motivation for the termination. Using the example above, an employee might prove that younger employees in the same position with equally high salaries were not laid off. He could also show that he volunteered to take a pay cut instead of being laid off, but his offer was refused.