Check Please

Friday, January 19th, 2007

James Surowiecki says, Check Please:

It’s instructive to consider the sort of things that tippers actually respond to. In one study, a waitress received fifty per cent more in tips when she introduced herself by name than when she didn’t. In another, waiters sharply increased their tips by giving each member of a dining party a piece of candy and then, seemingly spontaneously, offering each person a second piece, too. Squatting by the table instead of standing, writing “Thank you” on the back of checks, and touching customers on their shoulders all measurably improved tips. And waitresses at an upscale restaurant who simply put flowers in their hair boosted their tips by seventeen per cent.

Welcome to ‘the Great Moderation’

Friday, January 19th, 2007

Welcome to ‘the Great Moderation’, Gerard Baker says:

Almost unnoticed, most of the industrialised world, especially the Anglo-Saxon part of it, has enjoyed a period of unprecedented economic stability.

Recessions were once as frequent and as regular as World Cups or general elections. Now, like hurricanes in Hereford, they hardly happen. The classic business cycle has worked for centuries in a simple, recognisable way. As an economy grows, inflation accelerates. Interest rates then rise, cutting borrowing and investment. That causes production to decline, pushing up unemployment and producing a recession. Between 1950 and 1982 the US had seven recessions, one every 4.6 years. The UK had the same number and frequency. In between those recessions, inflation rose, reaching a higher peak in each cycle.

But something historic has happened in the past quarter of a century. The business cycle has not been abolished, but in the US and the UK, it has been stretched, to improbably great lengths. In the process, the wild fluctuations of employment, output, inflation and interest rates have been firmly damped. The peaks of inflation have been lower, and the troughs of output shallower.

As Gordon Brown constantly reminds us, the UK has not had a traditional recession for 15 years. Since the bottom of the slump of the early 1980s there has been only one recession in the past quarter of a century. The US did have a recession relatively recently, but a very short and shallow one; the previous one, in the early 1990s, was similar.

Economists have coined a term for this remarkable period of stability. Taking their cue from the Great Depression of the 1930s and the Great Inflation of the 1970s and 1980s, they have called the current era the Great Moderation.

The Big Three

Friday, January 19th, 2007

Arnold Kling opens his most recent essay, The Big Three, by citing Andrew J. Coulson:

We have been inexorably centralizing control over the schools in this country for 150 years. We’ve gone from one-room schoolhouses overseen directly by the parents of the children who attended them to sprawling bureaucracies that consume half of the operating budgets of their respective states. We’ve gone from 127,000 school districts in 1932 to fewer than 15,000 today — despite a massive increase in the number of students.

One of Kling’s “big three” issues is education — and limiting the damage done by government bureaucratization of schooling:

For example, in Montgomery County, Maryland, where I live, the local newspaper gave the following figures about the school Budget: total enrollment, 137,798; total employees, 21,840; total budget $1.98 billion; percent of budget devoted to employee compensation, 89%.

Using those numbers, it is easy to calculate that the ratio of students to employees is 6.3, even though the typical class size is probably 4 times that amount. A clear inference is that most of the employees are not classroom teachers. However, these non-teaching staff are well compensated, since another exercise in simple arithmetic shows that the average compensation per employee is $80,686.

As a parent, I have observed that the really bad teachers and the really good teachers are destined for administrative positions. For bad teachers, administration is a place where the County can hide them. For good teachers, administrative positions are a reward, offering higher pay along with freedom from the extra workload of classroom teaching (the non-class time required to grade papers, prepare lessons plans, and so on) as well as its emotional stresses.

High Schools Starting Later to Help Sleepy Teens

Friday, January 19th, 2007

Finally. High Schools Starting Later to Help Sleepy Teens:

Most high schools begin their day around 7:30 a.m., which leaves many teenagers nodding off in the morning. In fact, at least 20 percent of high school students fall asleep in class on a typical day. The problem: Teenagers need a lot of sleep — about nine hours each night, experts say. And most of them aren’t getting enough.

To help sleepy teens, some school districts have tried delaying the opening of the high school day. Educational researcher Kyla Wahlstrom, from the University of Minnesota, has been following districts that changed their start times, tracking the effect on schools and students. The Minneapolis school district, for example, changed its start time from 7:20 to 8:40 a.m., giving its 12,000 high schoolers an extra hour and twenty minutes each morning. Wahlstrom says the students have benefited from the change.

“Students reported less depression when there was a later starting time,” she says. “And teachers reported that students were more alert and ready for learning. Parents reported that their children were easier to live with because their emotions were more regulated.”

Additionally, Wahlstrom found a decrease in the number of students who were dropping out of school or moving from school to school.

According to the National Sleep Foundation, more than 80 school districts around the country have now made the change to start their high schools later. These districts range from large, urban school districts, such as Minneapolis and Denver, to suburban districts, such as Jessamine County in central Kentucky.

Really, why, if a typical job starts at 9:00 AM, would you have teenagers start school at 7:30 AM?

Would cocaine legalization help Colombia?

Thursday, January 18th, 2007

Would cocaine legalization help Colombia?:

Legalizing or decriminalizing cocaine would do much to improve America’s inner cities and it ought to be seriously considered, even if it means more doped-up middle-class white teenagers. But legalization — whether in Colombia or the United States — is not obviously the way out for Colombia.

The positive scenario is that legalization eliminates the profits from the drug trade and the Colombian nasties pack up shop and go away. In a legal market, Merck would outcompete the drug barons. Maybe they would grow more coffee.

I see two negative scenarios. First, cocaine production has been a boon to the Colombian economy. It is no accident that Colombia experienced no currency crisis, unlike most other Latin countries. (For contrast, here are some arguments that cocaine has hurt the Colombian economy; I don’t believe it.) The rural Colombian economy might well collapse, taking civil order with it.

Second, the Colombian civil war is 40 years old and it predates the importance of cocaine. Narco-traffickers set up processing labs in Colombia because the government did not control the country in the first place. Legalizing cocaine would devastate their incomes, and probably bring political assassinations and military conflicts into the capitol. It is not clear Colombia can handle it. Keep in mind these same groups once, when threatened with more extraditions, stormed the Supreme Court and almost got away with it. Cocaine profits, however evil they may be, give the guerrilla groups some stake in the status quo.

That said, cocaine legalization probably would have helped Colombia in the late 1970s, before the paramilitaries became so rich. That doesn’t mean the same idea will work today.

Can hot water freeze faster than cold water?

Thursday, January 18th, 2007

Can hot water freeze faster than cold water? For years, folklore said yes, while science said no — until a Tanzanian student named Mpemba brought attention to the phenomenon, which still isn’t well understood:

What follows below is a short description of the four related mechanisms that have been suggested to explain the Mpemba effect. More ambitious readers can follow the links to more complete explanations of the mechanisms, as well as counter- arguments and experiments that the mechanisms cannot explain. It seems likely that there is no one mechanism that explains the Mpemba effect for all circumstances, but that different mechanisms are important under different conditions.
  1. Evaporation — As the initially warmer water cools to the initial temperature of the initially cooler water, it may lose significant amounts of water to evaporation. The reduced mass will make it easier for the water to cool and freeze. Then the initially warmer water can freeze before the initially cooler water, but will make less ice. Theoretical calculations have shown that evaporation can explain the Mpemba effect if you assume that the water loses heat solely through evaporation [11]. This explanation is solid, intuitive, and evaporation is undoubtedly important in most situations. However, it is not the only mechanism. Evaporation cannot explain experiments that were done in closed containers, where no mass was lost to evaporation [12]. And many scientists have claimed that evaporation alone is insufficient to explain their results [5,9,12].
  2. Dissolved Gasses — Hot water can hold less dissolved gas than cold water, and large amounts of gas escape upon boiling. So the initially warmer water may have less dissolved gas than the initially cooler water. It has been speculated that this changes the properties of the water in some way, perhaps making it easier to develop convection currents (and thus making it easier to cool), or decreasing the amount of heat required to freeze a unit mass of water, or changing the boiling point. There are some experiments that favor this explanation [10,14], but no supporting theoretical calculations.
  3. Convection — As the water cools it will eventually develop convection currents and a non-uniform temperature distribution. At most temperatures, density decreases with increasing temperature, and so the surface of the water will be warmer than the bottom — this has been called a “hot top.” Now if the water loses heat primarily through the surface, then water with a “hot top” will lose heat faster than we would expect based on its average temperature. When the initially warmer water has cooled to an average temperature the same as the initial temperature of the initially cooler water, it will have a “hot top”, and thus its rate of cooling will be faster than the rate of cooling of the initially cooler water at the same average temperature. Got all that? You might want to read this paragraph again, paying careful distinction to the difference between initial temperature, average temperature, and temperature. While experiments have seen the “hot top”, and related convection currents, it is unknown whether convection can by itself explain the Mpemba effect.
  4. Surroundings — A final difference between the cooling of the two containers relates not to the water itself, but to the surrounding environment. The initially warmer water may change the environment around it in some complex fashion, and thus affect the cooling process. For example, if the container is sitting on a layer of frost which conducts heat poorly, the hot water may melt that layer of frost, and thus establish a better cooling system in the long run. Obviously explanations like this are not very general, since most experiments are not done with containers sitting on layers of frost.

Finally, supercooling may be important to the effect. Supercooling occurs when the water freezes not at 0° C, but at some lower temperature. One experiment [12] found that the initially hot water would supercool less than the initially cold water. This would mean that the initially warmer water might freeze first because it would freeze at a higher temperature than the initially cooler water. If true, this would not fully explain the Mpemba effect, because we would still need to explain why initially warmer water supercools less than initially cooler water.

How far can bullets travel when fired into water?

Thursday, January 18th, 2007

If you watch Mythbusters, you already know the answer to this question, How far can bullets travel when fired into water?:

The first candidate for this test was the Civil War rifle. At a range of 15 feet, the ballistics gel was completely unharmed; likewise at five feet. Only when the range was reduced to three feet did the bullet finally penetrate the gel, suggesting that diving under water was probably a pretty effective way of dodging slugs during the Civil War.

The experimenters moved on to the hunting rifle, which was loaded with a full-metal jacket .223 round that emerged at roughly 2,500 feet per second. At ten feet, the bullet disintegrated and the gel was untouched. At three feet, the bullet again broke up, with its tip coming to rest on the gel — not nearly enough power to damage flesh.

A bullet from the M1 Garand, with a muzzle speed of 2,800 ft/sec, also disintegrated at the ten-foot range. At two feet, the slug penetrated about four inches into the gel, suggesting a non-fatal wound. The armor-piercing .50 caliber round didn’t do any better — it, too, came apart at distances greater than five feet and lost most of its punch by three feet.

Here’s where it gets interesting:

The engineers at the Central Scientific Research Institute for Precision Machinery Construction in Moscow correctly perceived the problem with shooting into water and in response developed the SPP-1 (Spetsialnyj Podvodnyj Pistolet, or “Special Underwater Pistol”) for use by Russian Navy frogmen. The SPP-1 is a manually operated four-barrel handgun that breaks open along the top and loads in a fashion similar to a double-barrel or over-and-under shotgun. The ammunition is designed to work underwater, using long bottlenecked rimmed casings plus bullets made from mild rather than hardened steel and designed to be stable underwater. The barrel isn’t rifled. According to the specs for the pistol, when fired at a depth of five meters — over sixteen feet — it’s lethal up to seventeen meters, or over fifty-five feet.

The SPP-1 isn’t the only exemplar of the breed. Other firearms are designed to work underwater as well, but they tend more towards the spear-gun model using dart-like projectiles. There’s no bright-line boundary where a bullet becomes a dart, but the projectiles fired by the Heckler & Koch P11 Underwater Pistol, for example, clearly cross the line. The H&K is an all-polymer weapon made especially for underwater use by the German Bundeswehr Kampfschwimmer — “army combat divers.” Each of the five dart-shaped projectiles is powered by a small, solid-fuel rocket. The weapon has been featured in some high-profile films, including Tomb Raider with Angelina Jolie, and is said to be able to inflict a fatal wound at fifty feet underwater.

Aztecs vs. Greeks

Thursday, January 18th, 2007

In Aztecs vs. Greeks, Charles Murray laments that we do not train our most gifted students to be wise, even though we expect them to end up in positions of great power and responsibility:

The gifted should not be taught to be nonjudgmental; they need to learn how to make accurate judgments. They should not be taught to be equally respectful of Aztecs and Greeks; they should focus on the best that has come before them, which will mean a light dose of Aztecs and a heavy one of Greeks. The primary purpose of their education should not be to let the little darlings express themselves, but to give them the tools and the intellectual discipline for expressing themselves as adults.

In short, I am calling for a revival of the classical definition of a liberal education, serving its classic purpose: to prepare an elite to do its duty. If that sounds too much like Plato’s Guardians, consider this distinction. As William F. Buckley rightly instructs us, it is better to be governed by the first 2,000 names in the Boston phone book than by the faculty of Harvard University. But we have that option only in the choice of our elected officials. In all other respects, the government, economy and culture are run by a cognitive elite that we do not choose. That is the reality, and we are powerless to change it. All we can do is try to educate the elite to be conscious of, and prepared to meet, its obligations. For years, we have not even thought about the nature of that task. It is time we did.

Apple reports record 1Q profit

Thursday, January 18th, 2007

Apple reports record 1Q profit:

For the final three months of 2006, profits surged 78 percent after the company sold a record 21 million iPod players, or about 50 percent more than it did in the same period the year before.

That’s an iPod sold for nearly every person in Texas. Sales of the iconic device accounted for $3.43 billion, or nearly half, of the company’s total revenue for the quarter.

Apple also shipped 1.6 million Macintosh computers, up 28 percent from the year-ago holiday season.
[...]
During its fiscal first quarter ended Dec. 30, the Cupertino-based company said it earned $1 billion, or $1.14 per share, compared with $565 million, or 65 cents a share, a year earlier.

Revenue for the quarter hit a record, reaching $7.1 billion, up 24 percent from $5.7 billion the previous year.

What’s Wrong With Vocational School?

Wednesday, January 17th, 2007

Charles Murray says that “too many Americans are going ot college.” What’s Wrong With Vocational School?:

There is no magic point at which a genuine college-level education becomes an option, but anything below an IQ of 110 is problematic. If you want to do well, you should have an IQ of 115 or higher. Put another way, it makes sense for only about 15% of the population, 25% if one stretches it, to get a college education. And yet more than 45% of recent high school graduates enroll in four-year colleges. Adjust that percentage to account for high-school dropouts, and more than 40% of all persons in their late teens are trying to go to a four-year college–enough people to absorb everyone down through an IQ of 104.

No data that I have been able to find tell us what proportion of those students really want four years of college-level courses, but it is safe to say that few people who are intellectually unqualified yearn for the experience, any more than someone who is athletically unqualified for a college varsity wants to have his shortcomings exposed at practice every day. They are in college to improve their chances of making a good living. What they really need is vocational training. But nobody will say so, because “vocational training” is second class. “College” is first class.

Really, college is a terribly inefficient way to provide the vocational training most people want:

For a few occupations, a college degree still certifies a qualification. For example, employers appropriately treat a bachelor’s degree in engineering as a requirement for hiring engineers. But a bachelor’s degree in a field such as sociology, psychology, economics, history or literature certifies nothing. It is a screening device for employers. The college you got into says a lot about your ability, and that you stuck it out for four years says something about your perseverance. But the degree itself does not qualify the graduate for anything. There are better, faster and more efficient ways for young people to acquire credentials to provide to employers.

Cheap, safe drug kills most cancers

Wednesday, January 17th, 2007

Cheap, safe drug kills most cancers:

It sounds almost too good to be true: a cheap and simple drug that kills almost all cancers by switching off their “immortality”. The drug, dichloroacetate (DCA), has already been used for years to treat rare metabolic disorders and so is known to be relatively safe.

It also has no patent, meaning it could be manufactured for a fraction of the cost of newly developed drugs.

Evangelos Michelakis of the University of Alberta in Edmonton, Canada, and his colleagues tested DCA on human cells cultured outside the body and found that it killed lung, breast and brain cancer cells, but not healthy cells. Tumours in rats deliberately infected with human cancer also shrank drastically when they were fed DCA-laced water for several weeks.

DCA attacks a unique feature of cancer cells: the fact that they make their energy throughout the main body of the cell, rather than in distinct organelles called mitochondria. This process, called glycolysis, is inefficient and uses up vast amounts of sugar.

Until now it had been assumed that cancer cells used glycolysis because their mitochondria were irreparably damaged. However, Michelakis’s experiments prove this is not the case, because DCA reawakened the mitochondria in cancer cells. The cells then withered and died (Cancer Cell, DOI: 10.1016/j.ccr.2006.10.020).

Michelakis suggests that the switch to glycolysis as an energy source occurs when cells in the middle of an abnormal but benign lump don’t get enough oxygen for their mitochondria to work properly. In order to survive, they switch off their mitochondria and start producing energy through glycolysis.

Crucially, though, mitochondria do another job in cells: they activate apoptosis, the process by which abnormal cells self-destruct. When cells switch mitochondria off, they become “immortal”, outliving other cells in the tumour and so becoming dominant. Once reawakened by DCA, mitochondria reactivate apoptosis and order the abnormal cells to die.

“The results are intriguing because they point to a critical role that mitochondria play: they impart a unique trait to cancer cells that can be exploited for cancer therapy,” says Dario Altieri, director of the University of Massachusetts Cancer Center in Worcester.

The phenomenon might also explain how secondary cancers form. Glycolysis generates lactic acid, which can break down the collagen matrix holding cells together. This means abnormal cells can be released and float to other parts of the body, where they seed new tumours.

Intelligence in the Classroom

Wednesday, January 17th, 2007

In Intelligence in the Classroom, Charles Murray explains that “half of all children are below average, and teachers can do only so much for them”:

Some say that the public schools are so awful that there is huge room for improvement in academic performance just by improving education. There are two problems with that position. The first is that the numbers used to indict the public schools are missing a crucial component. For example, in the 2005 round of the National Assessment of Educational Progress (NAEP), 36% of all fourth-graders were below the NAEP’s “basic achievement” score in reading. It sounds like a terrible record. But we know from the mathematics of the normal distribution that 36% of fourth-graders also have IQs lower than 95.

What IQ is necessary to give a child a reasonable chance to meet the NAEP’s basic achievement score? Remarkably, it appears that no one has tried to answer that question. We only know for sure that if the bar for basic achievement is meaningfully defined, some substantial proportion of students will be unable to meet it no matter how well they are taught. As it happens, the NAEP’s definition of basic achievement is said to be on the tough side. That substantial proportion of fourth-graders who cannot reasonably be expected to meet it could well be close to 36%.

The second problem with the argument that education can be vastly improved is the false assumption that educators already know how to educate everyone and that they just need to try harder–the assumption that prompted No Child Left Behind. We have never known how to educate everyone. The widely held image of a golden age of American education when teachers brooked no nonsense and all the children learned their three Rs is a myth. If we confine the discussion to children in the lower half of the intelligence distribution (education of the gifted is another story), the overall trend of the 20th century was one of slow, hard-won improvement. A detailed review of this evidence, never challenged with data, was also part of “The Bell Curve.”

North Korean Propaganda Posters

Wednesday, January 17th, 2007

Everybody loves North Korean Propaganda Posters, right? The typical text:

“Bear this in mind, world. Those who mess with our great undertaking will become our target.”

What’s Wrong With Vocational School?

Wednesday, January 17th, 2007

Charles Murray says that “too many Americans are going ot college.” What’s Wrong With Vocational School?:

There is no magic point at which a genuine college-level education becomes an option, but anything below an IQ of 110 is problematic. If you want to do well, you should have an IQ of 115 or higher. Put another way, it makes sense for only about 15% of the population, 25% if one stretches it, to get a college education. And yet more than 45% of recent high school graduates enroll in four-year colleges. Adjust that percentage to account for high-school dropouts, and more than 40% of all persons in their late teens are trying to go to a four-year college–enough people to absorb everyone down through an IQ of 104.

No data that I have been able to find tell us what proportion of those students really want four years of college-level courses, but it is safe to say that few people who are intellectually unqualified yearn for the experience, any more than someone who is athletically unqualified for a college varsity wants to have his shortcomings exposed at practice every day. They are in college to improve their chances of making a good living. What they really need is vocational training. But nobody will say so, because “vocational training” is second class. “College” is first class.

Really, college is a terribly inefficient way to provide the vocational training most people want:

For a few occupations, a college degree still certifies a qualification. For example, employers appropriately treat a bachelor’s degree in engineering as a requirement for hiring engineers. But a bachelor’s degree in a field such as sociology, psychology, economics, history or literature certifies nothing. It is a screening device for employers. The college you got into says a lot about your ability, and that you stuck it out for four years says something about your perseverance. But the degree itself does not qualify the graduate for anything. There are better, faster and more efficient ways for young people to acquire credentials to provide to employers.

Intelligence in the Classroom

Wednesday, January 17th, 2007

In Intelligence in the Classroom, Charles Murray explains that “half of all children are below average, and teachers can do only so much for them”:

Some say that the public schools are so awful that there is huge room for improvement in academic performance just by improving education. There are two problems with that position. The first is that the numbers used to indict the public schools are missing a crucial component. For example, in the 2005 round of the National Assessment of Educational Progress (NAEP), 36% of all fourth-graders were below the NAEP’s “basic achievement” score in reading. It sounds like a terrible record. But we know from the mathematics of the normal distribution that 36% of fourth-graders also have IQs lower than 95.

What IQ is necessary to give a child a reasonable chance to meet the NAEP’s basic achievement score? Remarkably, it appears that no one has tried to answer that question. We only know for sure that if the bar for basic achievement is meaningfully defined, some substantial proportion of students will be unable to meet it no matter how well they are taught. As it happens, the NAEP’s definition of basic achievement is said to be on the tough side. That substantial proportion of fourth-graders who cannot reasonably be expected to meet it could well be close to 36%.

The second problem with the argument that education can be vastly improved is the false assumption that educators already know how to educate everyone and that they just need to try harder–the assumption that prompted No Child Left Behind. We have never known how to educate everyone. The widely held image of a golden age of American education when teachers brooked no nonsense and all the children learned their three Rs is a myth. If we confine the discussion to children in the lower half of the intelligence distribution (education of the gifted is another story), the overall trend of the 20th century was one of slow, hard-won improvement. A detailed review of this evidence, never challenged with data, was also part of “The Bell Curve.”