The difficulty in proving age discrimination employment cases

While age discrimination remains an issue for millions of Americans, proving that their employers fired them because of their age is a difficult task for older workers. Nearly 21,000 people filed age discrimination complaints with the Equal Employment Opportunity Commission (EEOC) in 2016. Age discrimination cases are costly and time consuming, which is why few are willing to commit to filing lawsuits. CNBC takes a look at the challenges older workers face in this story.