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August 31st, 2009 (Permalink)

What's New?

Another installment in the ongoing translation of The Fallacy Files into Spanish: Negación de un Término de la Conjunción. I'm afraid that while I was at it I couldn't help but extensively revise the entry for Denying a Conjunct―the entry that was translated―so the new Spanish entry is out of date as soon as it goes public! However, having a translation of the previous version of the page is better than having no Spanish page at all. As always, if you see any errors in the translation or elsewhere, please let me know.

Update (10/8/2013): Unfortunately, the Spanish version of this entry no longer exists.

August 21st, 2009 (Permalink)

Blurb Watch Double Feature:
Inglourious Basterds & Bandslam


• (8/28/2009) According to Lou Lumenick, the new movie Inglourious Basterds is "the most fun you'll have at the movies this summer". Or, maybe not. Here's what the ad for the movie left out of its blurb:

Not your grandfather's or (father's) World War II epic, Quentin Tarantino's extremely witty revenge fantasy "Inglourious Basterds" MAY BE the most fun you'll have at the movies this summer.

Of course, the words "may be" are not capitalized in the original sentence, but neither is the rest of the sentence capitalized, as it is in the blurb.

Source: Lou Lumenick, "Mensch Warfare: Glorious 'Basterds'", The New York Post, 8/20/2009

'SENSATIONAL FOR ALL AGES.  WONDERFUL!  The musical performances engulf you in a sense of awe.'  -Janet Stokes, FILM ADVISORY BOARD

• The ad for the new movie Bandslam has an enthusiastic blurb from Janet Stokes of something called the "Film Advisory Board". The quote is not taken out of context, as far as I know, though I couldn't find a source for it online other than the ad itself. Who is Janet Stokes and what is the Film Advisory Board? Here's what Gelf Magazine found out for its "The Blurbs" feature when it looked into a blurb of hers for the movie Deck the Halls:

It seems that no one else has much nice to say about this putridly-reviewed Christmas movie, so Gelf called up Stokes to see what she liked about the movie (and to ask her why we weren't able to find the rest of her review anywhere). As it turns out, the Film Advisory Board doesn’t review movies per se, it just determines which ones are suitable for children. "We're not critics," Stokes says. "Critics are people who say the 'yay' or the 'nay'. We don’t do that. If we can't say something good about a film, we don’t give them an award." For certain movies that the Board is invited to prescreen and decides to bestow its award upon, Stokes will submit a positive blurb to the film's publicity team, as in the case of "Deck the Halls." Complicating this relationship, though, is that the Film Advisory Board relies on donations from the movie studios to stay in business. Stokes maintains that the funding plays no role in deciding which movies to grant awards or blurbs.

Yet, the blurb appears at the top of the ad above a couple of other blurbs by presumably real critics. Unless you happen to know, as I did, what the Film Advisory Board is, you're not likely to realize that Stokes doesn't profess to be a critic. Moreover, the blurb itself sounds like part of a rave review, rather than just a judgment that the movie is acceptable for all age groups.

Source: David Goldenberg, "The 'Gone with the Wind' of Rock Comedies", Gelf Magazine, 12/1/2006

August 15th, 2009 (Permalink)

The Back of the Envelope

Allstate insurance company is running an ad campaign supporting a piece of legislation called the "STANDUP Act of 2009", which would withhold federal highway funds from states that don't adopt a graduated driver's license―which is a sort of probationary license for beginners―together with some other measures intended to reduce the number of car accidents caused by novice drivers. At the top of one of its ads, Allstate makes the following claims:

Last year, nearly 5,000 teens died in car crashes.

Making it safer for a teen to be in a war zone than on a highway.

The only justification given for these claims is in fine print at the bottom of the ad:

Sources: Insurance Institute for Highway Safety Fatality Facts 2006, 2007 (latest data available); Centers for Disease Control and Prevention 2008.

Presumably, the IIHS data would support the claim of 5,000 teen fatalities last year, though neither of the fact sheets listed are for 2008. However, the number of fatalities probably changes little from year to year, so 5,000 may be a good approximation for last year. That's not what worries me, since the number is plausible. What I wonder about is the justification for the claim that this level of fatalities is worse than a war zone, which sounds implausible. Of course, the fact that the claim is surprising is what makes the ad effective. You're supposed to read it and think: "A teen is safer in a war zone than in a car? Wow! I didn't know that!"

However, the notion of a "war zone" is highly vague: Is Iraq currently a war zone? Omaha Beach on D-Day was surely a war zone, but also a much more dangerous place for a teen―or anybody else, for that matter―than driving in America. So, what "war zone" was the basis for comparison? I wrote to Allstate asking for the justification of the claims made in the ad, and received the following reply:

The Washington Post has found that 1,019 total U.S. soldiers were killed in 2007. (This statistic includes soldiers of all ages). In 2007, nearly 5,000 teenagers were killed on U.S. roads, according to the National Highway Traffic Safety Administration.

Our goal is to raise awareness that teenagers have the ability to make better decisions and to change their driving habits. We believe we can accomplish this through compelling messages that underscore the very real dangers of teen driving.

So, Allstate compared the absolute numbers of teens killed on American roads with the absolute numbers of American soldiers killed in Iraq. Now, it's doubtful whether Iraq in 2007 was still at war, and therefore a war zone―at best, it's a borderline case. Moreover, even if it was a "war zone", it was an atypically peaceful war zone, and thus one that is likely to make war zones appear less dangerous than they really are.

However, even accepting that Iraq in 2007 was a typical war zone, the comparison doesn't support the ad's claim. The absolute number of American soldiers killed in war zones is partly a function of how many soldiers are there, just as the absolute number of teens killed in car accidents in the U.S. is partly determined by the number of teens here. There were far more teens in the U.S. than American soldiers in war zones, so it needn't be surprising that more teens died than soldiers.

What should Allstate have compared? Since the claim has to do with the comparative safety of driving and warfare, we need some measure of safety. Absolute numbers of deaths are not a good way to measure the safety of activities, since they are so affected by the number of people who take part in the activity. For instance, taking a bath is much safer than skydiving, but the absolute number of people killed while taking a bath is going to be much larger than the number killed skydiving, because many more people bathe than skydive, thankfully. Instead of comparing the absolute numbers, a better comparison would be the death rates of the activities, that is, the fraction of bathers killed compared to the fraction of skydivers killed.

So, what fraction of American teens were killed in car accidents in 2007? What fraction of American soldiers were killed in action? Here's where you should pull out your envelope or cocktail napkin and begin figuring. Of course, it's Allstate's ad and it isn't up to you to support their claim, but at least you can check it for plausibility. Moreover, it will be good practice in doing "back of the envelope" plausibility checks of claims made in the media.

See the Back of the Envelope


Acknowledgment: Thanks to David Orth for supplying the example.

'****!' Ben Kenigsberg, Timeout Chicago David Fear, Timeout New York Mick Lasalle, San Francisco Chronicle
August 14th, 2009 (Permalink)

Blurb Watch: In the Loop

I've mentioned in previous "Blurb Watch"s the fact that movie critics' star ratings are ambiguous, since you need to know how many stars are possible to understand them. Some critics use a six-star system, more have a five star limit, and most make do with only four. As a result, adwriters for movies love to use four star ratings, as in the ad for the new movie In the Loop, since four stars is usually the highest possible rating. However, some movie ads, such as that for In the Loop, print four-star reviews from critics that have more stars to give, but the ads don't indicate how many stars were possible.

The In the Loop ad cites three different critics giving the movie four stars, but two of these―the critics for Timeout New York and Timeout Chicago―were using a five-star scale. The third reviewer―Mick Lasalle of the S.F. Chronicle―doesn't appear to use a star system at all, but does give at least four ratings: Below Average, Good, Very Good, and Excellent. Lasalle gave the movie an "Excellent" rating, which seems to be the highest possible, so this is the only "four star" of the three that isn't misleading. In contrast, the two Timeout critics give the movie an 80% rating, which is very good but not "excellent".


August 12th, 2009 (Permalink)

The Puzzle of the Three Houses

  1. During the years that Larry owned a house, the overall rate of inflation was 25%. When he got a new job in a different town, he was able to sell the house for 20% more than he paid for it.
  2. During the time that Curly owned a house, there was a period of deflation during which the average cost of goods and services fell by 25%. Curly lost her job and had to sell the house for 80% of what it cost her.
  3. The average price of goods and services was nearly the same at the end of the period of Mo's home ownership as at the beginning, and she sold her house for the same amount that she had bought it for years earlier.

Who came out best financially from their home ownership? Who did the worst? Rank the three homeowners from best (1) to worst (3).


August 7th, 2009 (Permalink)


Indonesia police storm Java house

I guess they don't have Dunkin' Donuts there.

August 6th, 2009 (Permalink)

Logic Check

House Republican leader John Boehner recently criticized a particular section of the House Democrats' healthcare bill as follows:

Section 1233 of the House-drafted legislation encourages health care providers to provide their Medicare patients with counseling on ‘the use of artificially administered nutrition and hydration’ and other end of life treatments, and may place seniors in situations where they feel pressured to sign end of life directives they would not otherwise sign. This provision may start us down a treacherous path toward government-encouraged euthanasia if enacted into law. … With three states having legalized physician-assisted suicide, this provision could create a slippery slope for a more permissive environment for euthanasia, mercy-killing and physician-assisted suicide because it does not clearly exclude counseling about the supposed benefits of killing oneself.

This is a classic "slippery slope" argument―specifically, a causal slippery slope―as Boehner himself indicates by his use of the phrase. Not all slippery slope arguments are fallacious, rather it depends on how slippery the slope is and how bad the thing at the bottom of the slide is. If the slope really is steep and slippery, then that is some reason for not venturing out onto it, for fear of sliding to the bottom. However, if the slope isn't very steep and there are natural footholds for stopping a slide, then there is little reason not to go as far down it as we wish. How steep and slippery is the slope in Section 1233?

First of all, notice how thoroughly hedged this argument is: it may "start us down a treacherous path", it could "create a slippery slope". Apparently, it's not even certain that the legislation will put us on that slope, rather it's just a possibility.

The section in question requires Medicare to pay for "end-of-life" counseling sessions that were previously not reimbursed. These sessions would be voluntary, so it's hard to see why anyone who went to one would feel pressured into doing something they wouldn't otherwise do. If they felt pressured, they could simply refuse to sign anything, or get up and leave.

One might think that once such sessions are being paid for by Medicare, they could be made mandatory and the bureaucracy could use them to try to pressure people to refuse expensive treatments. However, what's to stop Congress from mandating such sessions now, bill or no bill? Nothing except for the predictable political fallout. Given Boehner's reaction to this section, imagine what would happen if Congress considered legislation that actually did what the current bill only "may" or "could" do!


Acknowledgment: Thanks to Will Arias for drawing the example to my attention.

August 5th, 2009 (Permalink)

Check it Out

Research shows that 91.539% of all numbers with three decimal places are made up by the writer just to impress you. The latest Numbers Guy column concerns overprecision:

…[D]ecimal places lend the aura of authority and the veneer of verisimilitude. So the modern world is awash in squishy numbers wearing the many-figured garb of faux precision.

Source: Charles Forelle, "When Precision Is Only 92.11567% Accurate", The Numbers Guy, 8/5/2009

The Back of the Envelope:

Allstate has given us the absolute numbers for teen road deaths and military deaths in 2007, which will be the numerators of the fractions. So, what we need for the denominators is the number of teens in the U.S. and the number of American soldiers in war zones in 2007. You could probably find those numbers through research, but a "back of the envelope" estimate should be enough for our purpose, which is to evaluate Allstate's claim for plausibility.

How many teenagers are there in the U.S.? How can we estimate it without looking it up? If we knew the total population, as well as the fraction of the population that is teenaged, then we could calculate the number we need. So, what fraction of the population is teenaged? There are seven teen years from thirteen to nineteen, so assuming that seventy is about the average lifespan, roughly ten percent of the population will be teenaged. The U.S. population in 2007 was around 300 million, so about thirty million of those are teens. Thus, the teen death rate from car accidents is around 5,000 out of 30,000,000. Therefore, approximately 1 in 6,000 American teens was killed in a car accident in 2007.

How many American soldiers were in war zones in 2007? Most American troops in war zones that year must have been in Iraq, though some were in Afghanistan. If I remember correctly, nearly 150 thousand American soldiers were in Iraq, and considerably less than that in Afghanistan. Let's be conservative and assume that the total number of those in war zones was 200 thousand. (This is conservative because overestimating the number of troops in war zones will tend to lower the death rate, which will help Allstate's argument). So, the death rate for soldiers in war zones was about 1,000 out of 200,000, that is, approximately 1 in 200.

So, the chance of being killed as a soldier in Iraq or Afghanistan was about thirty times greater than the chance of a teen dying in a car accident. Of course, this is only an estimate, but the difference in rates is so great that there would have to be a large error in one of the numbers used to significantly change the result.

I made the above "back-of-the-envelope" calculation without doing any research, but just using what I already knew. Afterwards, I did a little research to be sure that what I remembered was not so far off as to falsify the result. According to the Wolfram Alpha computational knowledge engine, the U.S. population in 2007 was 306 million, and the average American lifespan was 78 years.

Wolfram Alpha doesn't seem to have any information on troop numbers, but I found a couple of New York Times articles from 2007 that did (see the Sources below): 165,000 in Iraq and 26,000 in Afghanistan, for a total of 191,000 in "war zones". Recalculating the rates using these more precise numbers makes no significant difference to the result.

I assume that this ad is not an example of how Allstate determines insurance rates. If so, they should charge people who bathe a much higher rate than skydivers!


Solution to the Puzzle of the Three Houses:

  1. Curly
  2. Mo
  3. Larry

Even though Larry sold his house for 20% more than he bought it for, the inflation rate of 25% meant that the actual value of the house had not kept pace with the rate of inflation, and he actually lost 5% of his investment. In contrast, even though Curly sold her house for 20% less than she paid for it, the deflation rate of 25% meant that the house had actually gained 5% in value, and that's how much of a profit she made. Of course, Mo broke even since she sold her house for the same amount that she bought it for, and there was no inflation or deflation to change the value of money.

If you came up with a different answer, it's probably because you didn't take the inflation and deflation rates into consideration. Inflation and deflation mean that money changes its value over time, so that it is a mistake to directly compare the monetary value of two items from different time periods. This mistake is called "the money illusion" because it is the illusion that an amount of money maintains the same value over time.

Source: Gary Belsky & Thomas Gilovich, Why Smart People Make Big Money Mistakes―and How to Correct Them: Lessons from the New Science of Behavioral Economics (1999). The puzzle was inspired by a similar one on page 107.

Acknowledgment (9/7/2009): The original version of this puzzle made reference to a mortgage on one of the houses, but the mortgage was not meant to be taken into consideration in solving the puzzle, so I've omitted mention of it. Thanks to Iwein Fuld for calling the problem to my attention.

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