Why do employers offer benefits to part-time employees?

Employers offer benefits to part-time employees to increase retention. Hiring and retraining new employees is expensive, and maintaining a supply of experienced part-time workers by offering competitive benefits is often the more cost-effective option for employers.

Additionally, tying benefits to a certain amount of hours worked per week helps reduce absenteeism and make staffing more reliable. Beyond all that, providing benefits to part-time workers shows them that they're appreciated, which makes for happier and more productive workers.