debitage: part of the core tool and scraper tradition

debitage

6.1.06

How To Write A Skeptical Post

Here's a challenge: find someone extolling the virtues of blind dogmatism. Everywhere you go, you find nothing but claims to be a clear-eyed rational assessor of the evidence. Even the most deeply religious people will tell you that their faith withstands open-minded scrutiny. Dogmatism is prevalent in today's world, but the Enlightenment has succeeded spectacularly in forcing it to disguise itself, even in the minds of its believers, as rational inquiry.

Why, then, do so many people feel the need to begin blog posts, newspaper columns, and other writings with a long discourse on the virtues of skepticism? There won't be any defenders of dogma popping up to take you on. I suspect that for many people, skepticism is an attitude, not a way of thinking. It makes you cool to extol your clear-eyed commitment to reason and the facts. It makes you righteous to see the truth where the masses have been led astray by unthinking allegiance to an unsupported theory. And it makes me skeptical of the quality of your analysis if you have to preface it by rehashing the same old arguments against dogmatism.

Anti-dogmatic generalities are a cheap rhetorical trick. They make the writer sound more important, since he's battling a grand social ideology rather than just a particular creationist argument, climate model, or Iraq policy. They demand that the reader take your side before the real argument has even begun -- after all, who wants to take the side of dogma?

People making skeptical arguments need to remember the cardinal rule of writing: show, don't tell. Don't tell me about the evils of dogmatism. Show me the evidence and show me how the prevailing conclusion doesn't follow from it. I, and everyone else, will be more likely to give your arguments fair consideration if you don't start off by accusing us of being unthinking sheep, and instead grant us the respect of making an argument about the topic at hand.

Stentor Danielson, 23:34, ,

Hybrid Irrationality, Hybrid Culture

Tim Haab wonders about the impact of saving gas money by buying a hybrid on consumers' purchase decisions. He notes a recent report that taxi drivers are jumping on the hybrid bandwagon, whereas regular consumers are slower to give up their conventional engines. Yet according to Haab's back-of-the-envelope calculations, the taxi drivers are only saving $455 more over the car's lifetime than the regular consumers. I can think of several reasons why taxi drivers might be more sensitive to the savings from hybrids than ordinary people:

1. The discount rate. Haab uses a typical 5% discount rate on the gas savings. But that assumes a high level of mathematical sophistication within the consumer's perceptual apparatus. A more likely thought process would be for the consumer to consider their gas costs over a more easily imagined short timespan -- say the first month. If those savings aren't a lot, they get rounded down to nothing, or next to nothing, before the consumer multiplies them over the lifetime of the vehicle. Because the savings don't show up as a big chunk (whereas the car price does), they get enervated by rounding. A business, on the other hand, would keep careful records of such expenditures, making it easier to be economically rational about them.

2. Separate budgets. Most people don't conceptualize their budgets as one big pool of money. In particular, big one-off purchases like a car are separate from recurring costs like gas. So when people head down to the car dealership, they aren't going to think very much about, or put very much weight on, trade-offs between gas and the sticker price. A business like a taxi, on the other hand, will tend to conform better to the kind of economic rationality that Haab's calculations presuppose. Both the car and the gas come out of the same bottom line for the taxi driver, so the potential for trade-offs is clear.

3. Culture. This, I think, is the biggest factor driving decisions to purchase or not purchase a hybrid. When you buy a car, you're not just buying just a mode of transportation and making a financial commitment, but you're also making a statement about who you are and what kind of people you associate with. Hybrids are very strongly associated with a particular culture -- the middle-class liberal greenie. This was a key to the early success of hybrids, as people snapped them up as a way of proclaiming themselves to be greenies. But that strong cultural association then inhibits the spread of hybrids to other sectors of society, particularly those who define themselves in part by their rejection of greenies' values and lifestyles. The cultural factor is weaker in the case of taxis, as people don't tend to pick their cab company as a cultural statement.

Stentor Danielson, 22:38, ,

5.1.06

Science Vs. the Death Penalty

This post by Philip Yam illustrates an common tendency to inflate the proportion of an argument that is proved by science. Yam claims that "Science has shown that our death penalty system is deeply flawed."

Yam makes two "scientific" arguments against the death penalty. First, he points out that science -- specifically DNA testing -- has exonerated at least one person and possibly more. Second, science has demonstrated the unreliability of eyewitness testimony, which is a crucial element of the evidence against most death row inmates.

All that is scientifically shown, then, is that our death penalty system cannot be relied on to be perfect in executing only the guilty. Or rather, that our criminal justice system is imperfect -- after all, eyewitness testimony is used against defendants sentenced to prison, too. It requires additional steps -- steps I happen to agree with, mind you -- to go from "imperfect" to "deeply flawed." One must evaluate the system's mistake rate as being too high, and believe that there's a meaningful difference between sentencing this mix of criminals and innocents to death or to life without parole. Yam treats this step as rather obvious, implying that if Americans only knew how many innocents were sentenced, they would reject the death penalty. But that fact is not so obvious -- after all, the guilty folks are pretty dangerous characters who richly deserve death (according to some ethical systems). Either way, though, this step is not a scientific one.

Stentor Danielson, 23:11, ,