How do I tell if something is a value or parameter in general?

My current guess is that something is a parameter if I can act in ways contrary to it, and be happier than if I followed it. It seems like time discounting is an approximation of how reality works so that humans can plan in ways that used to be accurate.

In this sense, I think that time discounting is a parameter. If I were able to do strategic things like save money in a compounding way so that I can retire significantly earlier, I would probably be happier than if I spent my money on say, candy bars and movie tickets.