Every Time You Hold A Door, God Kills A Kitten

This is kind of a frivolous example, but it highlights some interesting things about utilitarian cost-benefit analysis:

Chivalry's Genocide Yes, the practice of holding doors open is equivalent to mass murder. As I have explained, your average door holding transaction destroys a few net seconds of productive life. The average male lifespan in America is 77.2 years. This is equivalent to 2,434,579,200 seconds. If we estimate that every door holding destroys 3 seconds, we need only have a little over 800 million door holding transactions to destroy one modern American male's life. Let's suppose the average American woman has 500 doors held inefficiently for her in her life, although I suspect the true number is far higher. That means for every 1.6 million American women one man has been killed. The female population of the United States is a little over 143 million, so America's women are or will be collectively responsible for the deaths of about 90 men. Not terribly significant, but now add in Western Europe and any other cultures that condone this barbarous practice. Add all of the women who have lived and died since this traditional began. Factor in the reduced lifespands of men before modern times. Whatever the numbers you use, you're sure to reach thousands of men murdered by holding doors open.

This is an amusing application of cost-benefit analysis to everyday life. Will Baude's response (where I found the link) builds on the traditional utilitarian reasoning about money -- a dollar is worth a different amount to different people -- to say that in this case time isn't worth the same to everyone. Baude isn't usually in much of a hurry, so given the chances that the person behind him is in a hurry, it isn't necessarily inefficient to hold the door.

I think a more complete response would have to challenge the assumption, made by Slithery D and accepted by Baude, that the costs and benefits should be measured in time or time-quality. There are significant other benefits to door-holding that need to be taken into consideration. Most important, I think, is the effect on sociability. The positive benefits of interacting with another person, even if just through the brief contact of door-holding, have value beyond the time saved. The closing of the door behind the person in front of you symbolically reflects the social atomism that is shown in failing to hold the door when dictated either by calculation of the benefits of communal feeling or by commonly accepted standards of politeness.

UPDATE: Upon further thought, I have to question the conversation about the issue that Slithery D posted on his blog. It seems like quite an inefficient use of his time. He must have known that his explanation was quite unlikely to convince them, and thus the tradeoff against the utility of letting them think he was a jerk is questionable. And even if they were convinced, he seems to believe that door-holding is something nearly always done by men for women, and thus his arguments wouldn't have led his hearers to improve their door use efficiency, since they were women. It could perhaps be justified by the sociability criterion, but as I noted above, that would also destroy his argument against holding doors.