At an area prison, the warden is trying a new initiative in…

At аn аreа prisоn, the warden is trying a new initiative in оrder tо reduce rates of angry altercations between inmates. In short, the warden feels that if they could reduce instances of verbal aggression, they would end up reducing rates of physical aggression and violence as well. Now, whenever an inmate raises his voice toward another inmate or staff member, the inmate loses their phone privileges for that entire week. What type of operant conditioning is at play in this example?