Final answer:
Employee referrals may not enhance workforce diversity as they tend to bring in similar candidates to the existing employee base, leading to homogeneity and potentially missing out on the innovation and customer appeal benefits of a diverse employee group.
Step-by-step explanation:
The recruiting source that is good but may not increase the diversity and mix of employees is employee referrals. While referrals can bring in candidates who fit the organizational culture and come recommended by current employees, they often do not contribute to a diverse workforce because employees tend to refer individuals who are similar to themselves. This can lead to homogeneity within an organization. To tackle discrimination in the labor market and promote diversity, professionalize their human resources functions, and acknowledge the benefits of a diverse workforce in fostering innovation and appealing to a broader customer base.