Results for “Tests” 772 found
Sentence of the Day – French Edition
Unexpected violence broke out in Lyon when a march of about 2,500 Turks
protesting against a memorial to Armenian victims of a 1915 massacre in
the then Ottoman Empire crossed paths with the anti-CPE demonstrations.
(From Reuters
regarding today’s huge protests in France against the new bill allowing
firms to fire young workers in their first two years of empolyment if
they don’t work out.)
At the Bastille
As I arrived at the Bastille Metro a mass of students exited, marched across the 5 lane roundabout and sat down. Chaos ensued. Unfortunately for them the road was so wide they could manage a blockade only 2 to 3 students deep. This was not enough as angry young french men with jobs drove their mopeds through the crowd kicking the students along the way. Apparently the workers of the world are not united, at least not in France. Unable to maintain their ranks the protest fell apart. Today, however, some 40,000 students protest across France and the police presence in Paris remains strong.
Here is my previous post describing the economics behind the protests.
At the Sorbonne
French riot police stormed the Sorbonne on the weekend, ousting students who had barricaded themselves in the first occupation since the events of 1968. I am in Paris (did you guess?) and the police presence at the Sorbonne is impressive, but student protests continue in the streets.
The students are protesting a new labor law which would make it easier to fire workers under the age of 26. Of course, this would also make it easier to hire young workers who currently have an unemployment rate of 23 percent. You cannot have it both ways; raise the cost of firing and you raise the cost of hiring. In my opinion, the Sorbonne students need a little less Foucault and a little more Bastiat.
Or perhaps the students know more economics than I credit them with. Under the current law it is costly to fire anyone but the effect on hiring is not symmetric. The workers least likely to be hired are those who are perceived, rightly or wrongly, as a risk. The fear of hiring effect falls not on the privileged students at the Sorbonne (trust me today’s protesters were tres chic), but on young French North Africans whose unemployment rate exceeds 30 percent.
Thus, paradoxical as it may seem, today’s protests by the Sorbonne elite are a cause of the riots of late last year.
The bottom line on the new Judith Harris book
If you think my theory is unnecessarily complex, just wait till you see what the theories will be like fifty years from now.
An excellent line but also a sign of trouble. The final sentence is:
Making a virtue of necessity, I will leave it to other people to test my theory [TC: in fairness to Harris, she may be referring to her medical problems].
Nonetheless I like virtually everything she says. The key point is that when it comes to environmental influences on our behavior, we are highly malleable avatars. Tests which don’t recognize this will be misleading. For instance if you are testing "birth rank" theories, submission within the family does not imply submissive behavior toward the outside world. Of course the theory immediately gains an additional degree of freedom, both its blessing and curse.
The book is full of fascinating facts and interludes:
…people who are married to one of a pair of twins feel, on average, only so-so about the other twin; only 13 percent of the men and 7 percent of the women feel they could have fallen for their spouse’s twin.
Dead Ringers anyone? Here is my previous post on the book.
The bottom line: All those young, anti-theocratic, and sometimes pro-democratic Iranian hotheads, for all their rebellious behavior against their parents, when push comes to shove will embrace nuclear weapons and a maximal sphere of regional influence.
Prudie blows it again
The question: I have a friend who is a functional alcoholic. Every day after work he stops by a bar, and within two hours consumes two pitchers of beer. Needless to say he drives home. He’s not sloppy drunk, nor does he exhibit signs of being drunk, but I’m sure his reaction time is impaired. Two years ago he was arrested for drunk driving. After hiring a lawyer who used to work as a police officer, he got the charges dropped to reckless driving. The lawyer advised him that next time he is pulled over not to submit to any tests, but to request a lawyer. He was pulled over again last week and did as he’d been advised. He spent the night in jail, allowing the alcohol level in his blood to drop, making it pointless to test him. I don’t want to see him get away with this anymore. I don’t know what to do. I fear that confronting him will do nothing. I feel if I make an ultimatum in regard to our friendship, he will choose alcohol, which won’t stop his drinking and driving. Part of me wonders if I should anonymously inform the police of information that would help prove their case against my friend, but I feel this would be a huge betrayal. I just want to stop this behavior and help him avoid harming an innocent bystander.
—Afraid for a Friend
Read Prudie’s answer here, but basically she says lie in wait for him at a bar and then call in the police to track him and arrest him. I suggest a different approach…
1. He shouldn’t be your friend in the first place.
2. Turning him in to the police will make him your ex-friend. That is in some ways a good start, but I suggest you have only weak duties to help your "soon to be ex-friends."
3. If you wish to help innocent bystanders, forget about your friend and stand outside a popular bar with a cell phone. Or work overtime and invest the money in third world micro-finance. There is no good consequentialist reason to target your friend’s drinking and driving. (Did I just call him your "friend"?) It is unlikely that is the area of your greatest effectiveness, especially since the guy doesn’t care much about you.
4. What is she trying to get out of her system? Has he neglected her in favor of the alcohol? Often you can infer the real motivations by taking the opposite of the "pen name," in this case "Afraid for a Friend."
Let us do one more:
Question: I have a fiance who has an anxiety problem for which he takes medication. He wants to bring his guitar with him on our honeymoon because he said since he can’t bring his piano (he’s a classically trained pianist), he needs some instrument to play. He said that he needs the guitar or else he will feel anxious, because he would not have any instrument to practice. It irks me to no end that if he doesn’t have an instrument and he’s sharing company with me, that’s what he’s focusing on even though we’re watching TV or at dinner, etc. When we have gone away for a weekend and he has not brought his guitar, he drinks instead. He does not get drunk, but he does drink enough over time that the alcohol keeps him from "performing." Is it selfish to want to have my honeymoon with just my husband and not have him leaving to go to another room to practice for a couple hours? I want undivided attention! Yet, I don’t want to have him drinking and not able to perform, nor yearning to play an instrument while he is with me. Shouldn’t I be enough, at least for our honeymoon?
—Feeling Not Important Enough
Prudie says you are a pain in the neck and you should split with a man you obviously do not love or even like. I’ve been known to offer this advice myself, but let’s give it another spin. There is a reason why "Feeling Not Important Enough" made a bad choice in the first place. If she splits with him, she will be "drawing from the urn without replacement," as they say. And what a very special urn it is. Should she think that simply making another choice will yield something much better? At least this first pick a) plays at least two musical instruments, and b) is taking medication, which is more than you can say for the median impotent, nervous, obsessive-compulsive, alcoholic musician.
Ugly Criminals
Mahalanobis points us to Ugly Criminals:
Using data from three waves of
Add Health we find that being very attractive reduces a young adult’s (ages
18-26) propensity for criminal activity and being unattractive increases it for
a number of crimes, ranging from burglary to selling drugs. A variety of tests
demonstrate that this result is not because beauty is acting as a proxy for
socio-economic status. Being very attractive is also positively associated with adult
vocabulary test scores, which suggests the possibility that beauty may have an
impact on human capital formation. We demonstrate that, especially for females,
holding constant current beauty, high school beauty (pre-labor market beauty)
has a separate impact on crime, and that high school beauty is correlated with
variables that gauge various aspects of high school experience, such as GPA,
suspension or having being expelled from school, and problems with teachers.
These results suggest two handicaps faced by unattractive individuals. First, a
labor market penalty provides a direct incentive for unattractive individuals
toward criminal activity. Second, the level of beauty in high school has an
effect on criminal propensity 7-8 years later, which seems to be due to the
impact of the level of beauty in high school on human capital formation,
although this second avenue seems to be effective for females only.
The best sentence I read last night
Expressed loosely, being smart makes women patient and makes men take more risks.
That is Shane Frederick, in the Fall 2005 issue of Journal of Economic Perspectives. Here is an on-line version of the paper. Here is Frederick’s home page. Here is his fascinating doctoral thesis, an exploration of discounting and personal identity over time.
Frederick dares the economist to judge some people as irrational rather than ascribing all differences to preferences or risk-aversion. Remember all those tests of expected utility theory? If subjects with high cognitive abilities tend to choose a certain way, should we not consider that the rational choice? For instance your ability to get simple numerical problems right is correlated with having a low rate of time preference. Also check out Frederick’s data on which schools have students with the highest cognitive abilities…poor Toledo University…
Carcinogenicity in rodents: does it matter?
On this topic I am strictly a funnel. Derek Lowe has written a response to Revere at Effect Measure, and his defense of "rat tests." Here is the link to the entire exchange. The authors have an instructive back-and-forth in the comments section.
Which sport has the most upsets?
Soccer looks random to my untutored eye and perhaps it is:
Eli Ben-Naim, Sidney Redner and Federico Vazquez at the Los Alamos National Laboratory in New Mexico decided to look at unpredictability of results – how often a team with a worse record overcomes an apparently superior one – as the best measure of how exciting a league is. "If there are no upsets, then every game is predictable and hence boring," says Ben-Naim.
The team analysed results from more than 300,000 games over the last century from the US’s national hockey, football, baseball and basketball leagues and the top English football league. Rugby and cricket were omitted because they do not have a big following in the US.
Their results showed that the "upset frequency" was highest for soccer, followed by baseball, hockey, basketball and finally American football. But when they looked only at data from the past 10 years, the English football Premiership and baseball swapped places, which suggests that soccer might have become more predictable in recent years.
Here is the story. I have long favored basketball. In any given year, barring major trades or injuries, only three or four teams (if that) have any chance of winning the title. You know who the titans are, and you know who the peons are. Limiting randomness and divvying up the ponds in this fashion boosts suspense and status. The old Celtics-Lakers match-ups were ideal. The league is driven by star teams and players, so let’s promote those stars. Chess has the same property, but a few good pitching nights can turn a World Series around.
The implied prediction is that basketball and football will have large bases of casually informed fans, typically relying on mass media. Baseball and soccer will have more fanatics, more trivia contests, and will be more deeply rooted in niche media. You have to know about many players and teams to figure out what is going on, who is likely to win, and why.
Plus ca change…
I had the same reaction as Pablo Halkyard at the PSD Blog to yesterday’s article in the NYTimes on Bolivian water privatization so here is his post:
Juan Ferrero’s
article in today’s New York Times discusses the poor results of water
privatization and nationalization in Bolivia, as well as the country’s
turbid future as it struggles to reform.After
days of protests and martial law, Bechtel – the American multinational
that had increased rates when it began running the waterworks – was
forced out. As its executives fled the city, protest leaders pledged to
improve service and a surging leftist political movement in Latin
America celebrated the ouster as a major victory, to be repeated in
country after country.Today, five years later, water is again as cheap as ever, and a
group of community leaders runs the water utility, Semapa. But half of
Cochabamba’s 600,000 people remain without water, and those who do have
service have it only intermittently – for some, as little as two hours
a day, for the fortunate, no more than 14.The sad
part is that I have read the exact same article by Juan at least four
times in the last two years – although sometimes the names of Peru or
Ecuador are plugged in for Bolivia, or electricty/gas replaces water as
the featured sector.
See also my earlier post on some surprising benefits of water privatization.
Extreme carcinogenic doses for rats
Here is a defense of using those rat tests to judge what will cause cancer in humans:
The "junk science" they are referring to is the long-standing and
well-confirmed practice of identifying chemicals likely to cause cancer
in humans by testing them in animals. The animals (rodents) are a
standard model for biological processes of relevance to humans (which
is why drug companies and medical researchers have been using them for
a century). They are well understood and are the only sentinels for
detecting carcinogenicity of any use to public health. Since chemically
induced cancer has a latency period of decades (typically 20 years or
more), waiting for it to appear in human populations would meant that
once detected, even if exposure would cease instantly (which can never
happen), it would take another 20 or more years to eliminate the
cancers from exposure (all the cancers induced in the 20 years exposure
prior to detection). But even then, the chances of detecting any but
the most powerful carcinogens in human populations (via epidemiology)
is small. Epidemiology is a very insensitive tool. I say this with some
authority, as I am a cancer epidemiologist specializing in chemical
exposures and have authored numerous peer reviewed studies in that area
over many years.
The main rhetorical lever ACSH employs is the
use of high doses in the animal studies, doses that are much higher
than usually faced by humans. But as ACSH knows well (but didn’t
divulge) there is a technical requirement for using these doses. If one
were to use doses in animals predicted to cause cancer at a rate we
would consider a public health hazard, we would need tens of thousands
of animals to test a single dose, mode of exposure and rodent species
or strain. This makes using those doses infeasible. Thus a Maximum
Tolerated Dose is used, one that causes no other pathology except
possibly cancer and doesn’t result in more than a 10% weight loss. The
assumption here is that something that causes cancer at high doses in
these animals will also do so at low doses. This is biologically
reasonable. It is a (surprising) fact, that most chemicals, given in no
matter how high a dose, won’t cause the very unusual and specific
biological effect of turning an animal cell cancerous. Cancer cells are
not "damaged" cells in the individual sense but "super cells," capable
of out competing normal cells. It is only in the context of the whole
organism that there is a problem. It is not surprising, then, that very
few chemicals would have be ability to turn a normal cell into a
biological super cell of this type. Estimates are that is far less than
10%, perhaps only 1% of all chemicals that have this ability. Thus
western industrial civilization doesn’t have to come to a screeching
halt if we eliminate industrial chemical carcinogens from our
environment.We know of no false negatives with this process.
Every chemical we know that causes cancer in humans also does so in
rodents (with the possible exception of inorganic trivalent arsenic,
which is equivocal).
Here is the full post. I’m not close to having the expertise to evaluate these claims, but two points. First, the author is highly qualified; as a blogger he is anonymous but I can vouch for his credentials. Second, it should be the self-appointed task of bloggers to pass along arguments which either struck them or which might shake up their readers.
Paying for Performance II
Roland Fryer’s experiment to pay school children for better grades will go into effect next year reports the New York Post.
Under the pilot, a
national testing firm will devise a series of reading and math exams to
be given to students at intervals throughout the school year.Students
will earn the cash equivalent to a quarter of their total score – $20
for scoring 80 percent, for instance – and an additional monetary
reward for improving their grades on subsequent tests….Levin
said details about the number of exams, what grades would be tested,
funding for the initiative – which would be paid for with private
donations – and how the cash will be distributed are still being
hammered out.…"There are people who are
worried about giving kids extra incentives for something that they
should intrinsically be able to do," Fryer said. "I understand that,
but there is a huge achievement gap in this country, and we have to be
proactive."
Thanks to Katie Newmark for the pointer.
Bad Statistics Lead to False Hope
Newspapers around the world are all agog with the story of a British Man, 25, ‘cured of HIV’; that headline from the normally reserved BBC. Scot is first in world to beat HIV says, (can you guess?), the Glasgow Sunday Mail. The more cosmopolitan, but doubly wrong, Medical News Today says, Man is Cured of AIDS. Other newspapers are reporting that doctors are "stunned," "mystified" and wondering whether this man holds the key to curing AIDS.
The story is pathetically simple once one gets past the headlines. A man tested positive for HIV, he took a lot of vitamins and just over a year later tested negative (several times). Now what are you going to believe that he cured himself of HIV or that the first test was wrong? HIV tests have high accuracy but when millions of people take these tests it’s an easy bet that there will be significant numbers of false positives.
It is even possible that in low-risk populations there will be more incorrect diagnoses than correct ones! Doctors may be stunned but to a statistician results like this are banal. Unfortunately, in about a dozen articles that I took a look at, many doctors were quoted (sadly, even the skeptical doctors were skeptical for the wrong reasons – they think the guy must still have HIV!) but not a single statistician. For the correct statistics see here or my earlier post, Why Most Published Research Findings are False, which analyzes a different application of the same idea.
HIV detection on demand
Ms. Brown would get her results in just 20 minutes, thanks to one of
two new tests that AIDS workers say have revolutionized testing for
H.I.V…On Thursday, the Food and Drug Administration’s Blood Products Advisory
Committee heard testimony on whether to recommend over-the-counter
sales of the rapid test for home use. The agency approved a home
testing kit in 1996, but users have to mail a blood sample to a
laboratory and wait for results by telephone.Proponents say
rapid testing in the home will reduce the stigma and other obstacles
that prevent many people, including one in four of the nearly one
million Americans who are infected with H.I.V., from getting tested and
starting treatment. Research shows that people who learn they are
infected are less likely to infect others.
Here are the details, note that test is an easy oral swab. I am not much worried about immediate suicides ("The most emotional responses come from negatives," says the article). But what are the further ramifications?
1. The test is in the hands of the individual, and the kit presumably does not issue a credible AIDS-free certificate. So perhaps we return to a greater reliance on trusting the word of the individual — "don’t worry, I tested negative a few weeks ago." Formal certificates of health might become less expected.
2. Will lovers-to-be ask for an on-the-site test? There is a stigma attached to asking a partner about his or her status. It suggests you often sleep with people whose health status you are unsure about; the alternative impression is "of course I’ve never done this before, and I bet you haven’t either. I’m not used to asking. HIV, what’s that?" And how much fun is it to watch a potential partner waiting for the results? Do you bring little consolation cards in case the test turns out badly? The resulting unwillingness to pry may further increase the reliance on verbal assurances. Again, the presence or lack of a certificate — however dated — may provide a clearer focal point and thus greater information and clarity.
3. How often should you test yourself? Given the signaling point from #2, what should you tell your next partner? That you test yourself every year? Every month? Every day? Which frequency would you find most reassuring in a potential partner? Keep in mind the probability of a lie or false result.
You can spin this one either way. You might assume that someone who self-tests every day has dangerous habits. Alternatively, you might assume (at least in pure theory) that the previous partners have been monitoring the test results, and that you don’t need to. "Hey, if two hundred people have slept with you in the last year, a few of them must have checked you out." Don’t you usually find the presence of other "customers" reassuring?
4. Say you test yourself after every new partner. You have a better sense of who infected you, which in turn identifies a greater number of infected agents in advance and also deters self-recognized infectors. Therefore people will test themselves less often than is socially optimal. The main benefits from testing may accrue to others, not to yourself.
Hmm…it’s not so simple after all. But I still believe this test is likely a positive development. Comments are open…
p.s. We thank Robin Hanson for his guest blogging!
Markets in everything: kidnapping and humiliation
These get harder to do each time (without descending into the gross, that is), but semagoediv [that’s "videogames" backwards] makes my life easy:
[Brock Enright] has had some 40 clients to date, and what they ask for can vary enormously. One woman he is currently working with in New York, in a game lasting several months, is trying to conquer her fear of deceit, and so, as if to inoculate her, Enright has inveigled around 25 new characters into her life, using actors. He has about 25 barmen on his books. “I’m not a therapist; I’m more like a cartoonist,” he says.
Of his kidnap subjects, some enjoy a three-day “game”, in which Enright and his team follow their movements and (subject to request, safety and various legal agreements) abduct them for around six hours before dumping them. I opted for the budget “Fantasy Photo” option, in which it was understood that the artist would stage a kidnapping and take a series of souvenir pictures. It was no picnic.
After our tea, Enright sent me off down a side street to wait. The precise form my adventure would take wasn’t clear until a Jeep careered around a corner, and figures in balaclavas jumped out and forced me into the back. I was hooded and held down. We drove a short distance and I was manhandled into what I later realised was an artist’s studio, and slammed down into the corner.
I won’t report the accompanying sexual humiliations, and yes the "weakies" are (supposedly) weeded out in advance by "psychological tests." Legal waivers are signed as well. Get this:
Kidnapping isn’t all he does, he emphasises, but his other projects seemed similarly unpleasant. They include one in which he simulates mass murders on a basketball court chalked up like a Ouija board, and another in which he acts as an internet counsellor encouraging suicide…
Here is the main story. Here is a story of how the torture of your kidnapping is custom-designed to match your fears. Enright has many repeat customers.