It covers my next-best alternative.

This might be my least favorite place on campus. I face this stairway every Monday, Wednesday, and Friday at 11:35 on the way to my microeconomics class. My body, weighed down by a heavy backpack and weak, especially this week, with sleep deprivation, starts hurting by the fifteenth step, and then I've still got ten to go. But I've decided that the marginal benefits of taking this class far outweigh this marginal cost. I'm not sure what I did before I could throw terms into conversation like "opportunity costs" and "next-best alternative" and "weighing the marginal costs and benefits" and "trade-offs" and "substitutes" and "comparative advantage." It's fun. I must be a nerd.

I was wait-listed for this class, but Dr. P.J. Hill was willing to write me in after I visited him in his office. I admitted I didn't "need" the class. There are "substitutes", you see, but I'm so glad he let me in anyway. He's such an interesting, engaging professor. I'm really grateful to be having this class at this time. He's spent a few class periods talking about the economic crisis. I'm not as clueless as I would be if I weren't in that class.

He's also just plain cool. He owns a ranch out in Montana that he will shortly be retiring to. Last week came to class dressed in carhartts, flannel shirt, cow-boy boots, and hat and lassoed the late comers. Then we learned about why a rancher and a farmer would benefit most from trade with each other if they specialized, thereby making the most of their comparative advantage.

The opportunity cost of writing more is growing too high as there are reading assignments I should get to.