Just kidding- this is the real reason that economics is called the dismal science, but just go with me here.
Economists are quick to point out that the true cost of something, whether it be a physical good, an activity, etc., is what one has to give up in order to get that thing. This cost includes both explicit costs, which are costs than involve an actual outlay of money or credit card or whatever, and implicit costs, which are the values of the other opportunities that have to be passed over in order to consume a good or perform an activity. One common implicit cost is the value of one’s time, since, by definition, time spent on one activity can’t be spent on other activities.
Economists use this concept of implicit cost (or opportunity cost, though the term “opportunity cost” is sometimes used to refer to the total of explicit and implicit cost) to make predictions about how many hours of labor people will supply. The logic is that, since every hour spent sitting on the couch and eating Cheetos (“leisure” in economic terms) is an hour not spent working, the implicit cost of sitting on said couch is an individual’s wage, since the wage is what the person would have earned by working for an hour instead. Over most normal ranges of wages, this would mean that, as sitting on the couch gets more expensive, people sit on the couch less and work more, which gives a positive relationship between a person’s wage and the number of hours that the person is willing to work.
I’ve taught this concept to my principles students for a number of years now, and I somehow never stopped to think about its depressing implications. Luckily, others have got my back on this:
Like a lot of people, the woman in the cartoon is good at thinking about explicit costs but not so good at thinking about implicit costs. I generally argue that not thinking about implicit costs is suboptimal because it leads to irrational decision making, but, after staring at this for a while, I’m beginning to think that ignorance might be bliss. I guess I can understand why that last graph doesn’t end up in college brochures very often.