Answer:
Union.
Step-by-step explanation:
Collaborative bargaining can be defined as a strategic process which typically involves a formal negotiation between an employer of labor (top executive or management) and a union representing the employees working in an organization so as to both reach an agreement on minimum wage, benefits and other pertinent working conditions.
The union and management agreement that allows non-union people to be hired but requires that they join the union after a probationary period creates the union shop.
Under a union shop, employers are saddled with the responsibility of either employing only labor union members or require that all new employees that aren't members of the union as at the time of employment become members after a probationary period i.e within a specific period of time.