Supply and demand
The basic economic law is all around us: when it rains, Uber hoofs up the price of a cab. In a line, it's the relationship between supply and demand that dictates the price people are willing to pay for a product or service. And maybe you see it elsewhere. Does it feel that people flirt with you more when you're in a committed relationship? That might be the law of supply and demand at work. When it comes to your time and attention, people just seem to want it more when someone else is getting it.