Centralized union wage bargaining with government intervention in sweden gives relatively more influence to while firm-level union wage bargaining in the united states gives relatively more influence to

I believe the answer is: outsiders; insiders
Centralize union bargaining with government intervention would most likely influence the regulations that would affect all labors within a specific state or nation, such as the regulation of mininum wage.
Firm-level union on the other hand, only influence the workers that work in one exact firm.