With every choice there is a cost. And that is true because every time we do one thing it means we can't be doing something else. Every time we spend a dollar on one thing it means we can't spend that dollar on something else. It means every action comes with an opportunity cost. That is something which we do not do because we choose to do the other thing. That is an opportunity foregone because we choose a different opportunity. With scarce resources like time that each of us have, we need to make choices in the world. And every time we choose to, for example, watch this video, you are choosing to watch this video and not watch something else or not be out playing with your kids or not be at work earning a paycheck. You are choosing to do one thing and you're losing the opportunity to do another. Economics helps us understand that idea of scarce resources and understand that the law must understand this as well, that when it forces people into one behavior it will necessarily close the door on perhaps another behavior. So the idea of opportunity costs become very important and tie in together with the idea of revealed preferences because if I know that you decide to watch this video you've revealed to me that you value this video more than you value the alternative things, the next best alternative thing you could be doing with your time. And you've revealed that. It may turn out, after the fact, that you, in fact, you second guessed yourself and you say, well, actually, I've watched this video and it wasn't very good. Or I've, I've done this thing, I thought I was going to enjoy seeing this movie and I didn't. We can always have those ex post evaluations of whether or not we think we made a good choice. But at the time we make a choice. We are deciding every time from a rational perspective based on our own individualized preferences and values how we want to spend that time and as a consequence we are rejecting all of the other alternative ways of spending our time as being less valuable to us. When the law can understand these kinds of ways people make decisions, it can better construct rules and it can better evaluate and support institutions to ensure that there is that space for people to make those best decisions, maximize their preferences, maximize human flourishing within the construct of the system.