Collective bargaining gives Union Members advantages over Nonunion members who hold the same jobs, skills, and characteristics (e.g. education, age, race, and gender). For example Union workers make on average 26% more then Nonunion workers. Most Nonunion workers are at will employees in most States. During negotiations we can bargain for a just cause clause and establish a guideline for discipline and corrective behavior, we can also negotiate for better wages, benefits, and working conditions( e.g. working hours, vacation, pension, 401k, sick leave, bereavement pay, etc.).
This graph from the Economic Policy Institute shows the economic impact from the decline of Unions. This graph speaks for it self as to why Unions are an important part of our economy, and why it is important to Organize and grow.