In proxy agency, what one person or group does, under appropriate conditions, counts as another agent or group having done something. Proxy agency is a common form through which institutional agency is expressed. For example, when an organization’s spokesperson performs an utterance act in the right conditions, the organization is taken to have announced something. When a corporation’s lawyers file bankruptcy papers, the corporation is said to file for bankruptcy. When the Senate ratifies a treaty, the United States is said to have entered into it. Proxy agency is not limited to groups. An individual may have a spokesperson, or assign a power of attorney to allow a proxy to close on a home sale. Even in these cases, proxy agency depends on a larger social context. How is proxy agency possible? What are its mechanisms? What does it show about institutional agency, in particular?