Like people, states might decide to form a union to increase prosperity for their citizens by bargaining with corporations as a collective. It makes it more d

Like people, states might decide to form a union to increase prosperity for their citizens by bargaining with corporations as a collective. It makes it more difficult for adversaries to overpower individual states in a union. This could consist of an obligation to uphold revenue (taxes) which is used to provide certain living standards (e.g. medical expenses, feeding grandma, etc...) through a social guarantee. How does corporate bargaining power work? Suppose two states and one corporation operating in both states. The corporation says to each state, "I'm reducing the employee count in your state unless you reduce my taxes." The threat is credible and is in neither state's interest. Unless the two states talk to each other and both agree to not reduce the tax rate, a social guarantee is in jeopardy. A union or cooperation of the states disallows the corporation the ability to punish and reward individual states, reducing the means to manipulate each individual state's tax rate to the corporations liking.