Have you ever had an argument with someone and then thought of the perfect comeback just after the debate is over? Yeah, me too. Rationalist bloggers must be the most susceptible people in the world, at least judging by the number of posts I’ve read that begin with “The other day I was talking to a friend about … and this is why they were wrong…”. Far be it for me to dismiss such posthumous rekindling of lost debates, I actually think that there’s much to be gained by mulling over interesting conversations after the fact. But this post isn’t about whistful comebacks, nor debates among friends, nor even updating beliefs. In fact, this whole first paragraph was simply a red herring so that the first line of my post would be something other than…The other day I was talking to a friend about and here is why their arguments were wrong.
The particular topic in question isn’t important here because I want instead to make a meta-observation about how people perceive costs and benefits. You see, when people weigh costs against benefits and see that one outstrips the other, the common reaction is to deny theexistence of the items on the losing side.
First case in point: climate change. It is my belief that, on balance, it would be a good thing if the government introduced regulations forcing new houses to be insulated for energy efficiency. The benefit is an energy-efficient future for the country. The cost is that houses would become slightly more expensive. On my reading, the benefits outweigh the cost. Weighing pros and cons is the right way to make a decision, but it does not in any way show that house prices will not increase, or that increasing house prices is not a bad thing. It simply claims that the bad part (increased house prices) is less bad than counterbalancing good parts (energy-efficiency).
There is no sense in denying that house prices will rise, or denying that rising house prices are a bad thing — that is to miss the point. The right decision hangs on the relative extent of the good and bad outcomes. If, hypothetically, the result of building regulations would be that house prices would soar to such an extent that (absurdly) every single person in the country would become homeless, then the costs would instead outweight the benefits, and building regulations would be a bad idea.
Second case in point: My college recently declared Thursdays as a meat-free day in hall. The benefits were that it would cause a surprisingly significant decrease in the college’s carbon footprint. The costs were that it reduced individual freedom. Those who know me know which side I supported, but the fallacy I want to point out in this post was perpetrated by both sides: While those in opposition were busy arguing that reducing carbon consumption was not really a good thing at all, those in favour ended up in contortions trying to show that personal freedom has no real merits at all! Clearly environmental friendliness and personal liberty are both good things; but the goodness or badness of meat-free days cannot be settled by either of those facts alone. It is settled by whether or not the costs outweigh the benefits; there is no sense in picking a side and then denying the very existence of arguments on the other side.
A hypothetical scenario illustrates the point: If, hypothetically, a meat-free day could save the entire planet from an impending apocalypse, then clearly it would be a desirable course of action. And if, equally absurdly, a meat-free day could only be accomplished by actually locking students in jail, then nobody would claim that it would be worthwhile. So reducing carbon consumption is a real benefit and enroaching personal liberty is a real cost. The argument cannot be settled simply by fixating on one or the other. The right choice is a matter of degrees, not absolutes.
So when making decisions, make sure to honestly weigh the costs against the benefits without being tempted to dismiss the existence of items on either side.