In exchange for agreeing to bargain in good faith with employees, employers get a guarantee that their employees will not strike. This is obviously of great benefit as regars police, fire, state corrections, and university employees. Second, collective bargaining affords employers the opportunity to preserve high employee morale through fair and equitable employment practices. In the public sector, collective bargaining generally improves relations both among employees and between employer and employees. Third, collective bargaining puts much of the burden of prioritizing desired changes on the employees themselves.
Employees come to the bargaining table with proposals.
Often employers find those proposals desireable.