Since you're the one advocating a system different from the status quo, the burden is on you to provide a serious analysis instead of a glib hypothesis. To use

Since you're the one advocating a system different from the status quo, the burden is on you to provide a serious analysis instead of a glib hypothesis. To use an Internet/cellphone analogy, sometimes is cheaper for the provider to just provide an "unlimited" plan instead of tracking usage. I'm almost certain the current system of universal firefighting coverage evolved from a previous system of privately purchased firefighters. In other words, I strongly suspect that the 'n' value here is "whole city".