Hans Rosling

The Sippy Diet

From Happy Accidents, Seredipity in Modern Medical Breakthroughs:

Doctors typically treated ulcers by initially ordering changes in a patient's diet, in an attempt to protect the stomach walls from its acid. The Sippy diet, introduced by Chicago physician Bertram W. Sippy in 1915, was practiced into the 1970's. Sippy called for three ounces of a milk-and-cream mixture every hours from 7:00 AM until 7:00 PM, and one soft egg and three ounces of cereal three times a day. Cream soups of various kinds and other soft foods could be substituted now and then, as desired. Accompanied by large doses of magnesia powder and sodium bicarbonate powder, such "feelings," as meals were known, would continue for years -- if not for life.

Unfortunately, the intake of food brings about not only increased saliva but also the production of stomach acid in preparation for digestion. The Sippy method was thus rarely unsuccessful because, though doctors didn't realize it, the diet actually increased level of stomach acid and therefore aggravated the symptoms of ulcers.
...
The fact that this falsely based approach nonetheless persisted for six decades illustrates the unfortunate fact that conventional wisdom once adopted remains stuck in place even when it flies in the face of reality

Beef and Sperm Production

The journal Human Reproduction has a article soon to be published describing the amount of beef eaten by mothers being related to son's sperm production (see here for a popular press account and here for the article). There are some interesting issues with a retrospective account of how much beef was eaten during pregnancy. Their key finding was that there was a negative correlation between sperm concentration and the mother's number of beef meals per week:

Sperm concentration was inversely related to mothers' beef meals per week (P = 0.041).

Interestingly, there are 387 people in this study and with a p-value of .041, there does not seem to be a strong correlation between these variables.

Government Economic Figures

The Social Science Statistics Blog has a great entry on the government new home sales figures. The 90% Confidence Interval around this number indicates that these figures are not significantly different from zero. Thus, when the press discusses these numbers as if they are real, they are quite likely making a Type I error. Below is a portion of the blog entry:

The government released its report on new home sales for the month of February; here is how the story was reported by Reuters (as seen on the New York Times website):

WASHINGTON, March 26 (Reuters) — Sales of new homes unexpectedly fell in February, hitting their lowest level in nearly seven years, according to a report released on Monday. New-home sales slid 3.9 percent, to an annual rate of 848,000 units, the lowest since June 2000, from a downwardly revised pace of 882,000 in January, the Commerce Department said. Sales for November and December were revised down as well.

And here is the Census Bureau press release:

Sales of new one-family houses in February 2007 were at a seasonally adjusted annual rate of 848,000, according to estimates released jointly today by the U.S. Census Bureau and the Department of Housing and Urban Development. This is 3.9 percent (±17.4%)* below the revised January rate of 882,000 and is 18.3 percent (±12.2%) below the February 2006 estimate of 1,038,000.

There are several amazing things about this. First, with all of the resources of the federal government, we can't get better than a 17.4% half-width for a 90% confidence interval?

Ted: Malcolm Gladwell

Suicide and Homicide

A great deal of attention is paid to homicide in our country. I see many more reports of murder in the news media than I do suicide. Very few suicides even make the news media and these reports are hardly ever the focus. It is interesting to note that there are almost twice as many suicides in the U.S. each year as there are homicides as seen in Table 2 of this CDC report.

This post describes how risks are assessed and in particular how the media can distort very small risks.

Risk Assessment

An earlier entry on this page discussed how people make more conservative decisions if they are posed with what they can lose in that decision (as opposed to making riskier choices if they are told what they can gain).

Another factor in our decision making process is risk assessment. That is, what are my chances at this loss if I do make that decision. People are generally very poor at making risk assessments. For example, some people are very afraid to swim in the ocean because of a fear of being bitten by a shark. There are thousands of people swimming in the water at any given moment of the day and there are on average 3 or 4 shark attacks a year. A person who is afraid of swimming in the ocean because of a fear of a shark attack is greatly overestimating the probability of a shark attack. There is actually a much greater chance of being killed in an automobile crash on the way to the beach than there is of being bitten by a shark.

The more grisly the image of the feared event, the more likely one will make a mistake in overestimating the probability of the event happening. For example, being in an airplane crash is a very frightening image. Being swallowed by an alligator is also very vivid.

Gary Becker, a well-known economist, put it very succintly in discussing the fear of flying:

“The terrorist plot to blow up from 7-10 planes with liquid explosives will once again increase the fear of flying. After the 9/11 horrendous attacks, U.S. domestic air travel was down by over 10 per cent for two years, and international travel on American airlines declined much further. The magnitude of this response went far beyond what could be explained by either the increased objective risk of flying or the greater time spent going through security. For even assuming that 3 planes a year on American airlines continued to be exploded by suicide bombers, air travel would still be a lot safer than traveling by car and bus, two major alternatives to air travel.”

Another factor in our risk assessment is our exposure to the feared stimulus. That is, the less exposure we have to the feared stimulus, the more we will be afraid of it. I believe one of the reasons we don’t overestimate the risk of being in a grisly car accident is because we are frequently in cars. By constant exposure to a feared stimulus, we make more accurate risk assessments (probably most people who surf daily have little fear of sharks).

A third factor in our overestimating risks, is the media. The media provides many new fears of which we ‘should’ be afraid. Livescience.com has an apt title for an article today: “Experts Say Don't Underestimate Threat of Morphing Monkey Viruses.” It may be unfair to single out Livescience.com because headlines of these sorts can be found anywhere. In their defense, they recently published a review of a paper discussing how the media omits facts in medical research. By paying attention to these type of media headlines (as well as gruesome images of unlikely events), we may be setting our risk assessments higher than we would otherwise.

People with anxiety have specific difficulties with risk assessment. For example, someone with social anxiety estimates the odds of making a social blunder much higher than is actually so. Asking someone with social anxiety the likelihood they will make a social blunder will be much higher than someone without social anxiety (Paradoxically, by avoiding social interactions they reduce their chance of practicing social skills and maybe actually increase the risk of social blunder.) A proven treatment for social anxiety (or other anxieties) consists of learning more about actually risks, so that a person can make better estimates of the actual risks involved. It also includes exposing him or her to the feared stimulus. With repeated exposure to what a person fears, he or she will become less anxious in those situations.

Scientists

Murray Gell-Mann, a Nobel laureate, has said this about scientists:

"The job of a scientist is to generate wrong ideas as fast as possible."

Science is Difficult

National Science Foundation: Science Hard

INDIANAPOLIS-The newly discovered 'Law Of Difficulty' holds true for all branches of science, from astronomy to molecular biology.

Helen Fisher on love, lust and antidepressants

Non-Zero Sum Game

Robert Wright talks in this video about non-zero sum games. These games are when the outcome for two people (or groups) is correlated. That is, if one player wins, the other one wins too (if one loses, the other one loses too). The analogue to that is the zero-sum game in which one person wins and the other person loses.

Often, situations are thought to be zero sum games when in actuality they can have more than one winner. Robert Wright discusses how working toward the mutual benefit can bring about great change. That is, many events are non-zero sum, so that our cooperation brings about a better good for all players.

Pleasure of Finding Things Out (part 2)

Pleasure of Finding Things Out (part 1)

Elizabeth Loftus on Scientific American Frontiers

Here and here is a great video discussing Elizabeth Loftus' newest work on the susceptibility of memory.

Terrorists - From the Freakonomics Blog

Steven Levitt writes about terrorism and flying in his blog today. Here is an excerpt:

The executives at American Airlines must be crazy. I heard a rumor — and I believe it is true — that they have made the decision to replace plastic knives with honest-to-God metal table knives in the first class cabin.

Are they crazy? Metal table knives were banned after 9-11 for good reason! Those things are dangerous. They could poke an eye out. There is no way the government, or whoever got rid of metal table knives after 9-11, would have banned them unless it was absolutely necessary to fight terrorism. This horrible decision to allow metal on the plane is simply an invitation to terrorists that they can come right on the plane unarmed, gather up these knives, and poke people at will. No honest citizen in his or her right mind would take the risk of flying on American in this new regime.

The next thing you know, TSA is going to allow me to fly with my 4.1 oz deodorant instead of throwing it in the garbage and rightly demanding that next time I limit myself to 3 oz. From what I hear, that extra 1.1 oz of deodorant is just the extra amount that terrorists need to turn deodorant into nuclear weapons from scratch on the plane. Apparently, though we have completely lost our will to fight terrorism in the sky.

(As an aside, I’m happy to say that my iPod listening during takeoff and landing continues not to cause the plane to crash.

From the Onion

Oscars Reveal Widening Gap Between Best, Worst Dressed

LOS ANGELES—"For every Sarah Jessica Parker, there's an overdressed underclass of Olsens and Abduls," style expert Melissa Rivers said of the country's widening taste gap.

Steven Levitt: the Freakonomics of inner-city gangs

iLaunch

Apple Unveils New Product-Unveiling Product

SAN FRANCISCO—Apple claims the iLaunch can garner the same amount of press attention as a major scientific discovery, high court ruling, celebrity meltdown, or natural disaster at 200 times the speed of a traditional media-fostered launch.

Dan Gilbert

College Rankings

Richard Posner writes an interesting blog entry about college rankings, such as U.S. News and World Reports rankings. In an earlier entry I spoke about recruiting undervalued college prospects. Posner's blog speaks about how students pick from the many Universities and how rankings convey information to the students. Here is an excerpt:

a ranking conveys an evaluation with great economy to the recipient; it gives the recipient an evaluation of multiple alternatives (in this case, alternative schools) at a glance. But a ranking's information content often is small, because a ranking does not reveal the size of the value differences between the ranks. One reason that disclosing the ranks of students has lost favor at elite colleges is that meritocratic standards for admission from a large applicant pool tend to create a student body most of which is rather homogeneous with respect to quality. The quality difference between number 1 and number 2, or between the top 10 and the bottom 10, may be very great, but the quality difference between number 100 and number 200 may be small, at least relative to the appearance created by such a large rank-order difference.

The information content of college rankings, as in the case of U.S. News & World Report's rankings, is particularly low because these are composite rankings. That is, different attributes are ranked, and the ranks then combined (often with weighting) to produce a final ranking. Ordinarily the weighting (even if every subordinate ranking is given the same weight) is arbitrary, which makes the final rank arbitrary. U.S. News & World Report ranks 15 separate indicators of quality to create its composite ranking of colleges.

The rankings, moreover, are manipulable by the schools, depending on the attributes that are ranked. A common attribute is the ratio of applications to acceptances. Both components of the ratio are manipulable--the number of applications by injecting a random element into acceptances, so that students who do not meet the normal admission criteria nevertheless have a chance of admission, which may motivate them to apply; and the number of acceptances by rejecting high-quality applicants who seem almost certain to be admitted by (and to accept) a higher-ranking school.

The effect of college ranking on the education industry is unclear, but my guess is that it is negative. The principal information conferred, given the information limitations of ranking in general and composite ranking in particular, is simply the rank of the college. But that is important to students (and their parents). And rightly so. Given the high costs of actually evaluating colleges, employers and even the admissions committees of professional and graduate schools are likely to give weight to a school's rank, and this will give applicants an incentive to apply to the highest-ranking school that they have a chance of being admitted to (if they can afford it). The result will be to increase the school's rank, because SAT scores and other measures of the quality of admitted students are an important factor in a college's ranking. That increase in turn will attract still better applicants, which may result in a further boost in the school's rank. The result may be that a school will attract a quality of student, and attain a rank, that is disproportionate to the quality of its teaching program. As a result, the value added by the college experience may be smaller than if rank were based solely on the quality of the college's programs, and so the students are getting less for their money than they could elsewhere. However, this conclusion must be qualified in the following important respect: the clustering of the best students at a handful of highly ranked schools may, regardless of the quality of the schools' programs, contribute to the human capital formation of these students by exposing them to other smart kids and embedding them in a valuable social network of future leaders. This may be a significant social as well as private benefit.

Implicit Association Test

The implicit association test is thought to gauge initial reactions of our attitudes. Creators of this test have looked at attitudes toward race, gender, and political affiliation. Other users of this test are looking at the clinical psychological applications. For example, does one have a implicit attitude that leads him or her to become depressed, socially anxious, or prone to panic attacks.

Here and here are links to a Scientific American Frontiers program on this test.

Richard Feynman

The video below shows Richard Feynman, famous Nobel laureate physicist, sharing some of his thoughts on how science adds to the wonderment of nature.

So this blog is not the worst

A writer at Wired magazine set out to create the worst blog in the world with her blog of pictures of crowds. Her story of the creation of this blog can be found here.

It is quite a relief that people are putting in effort to create blogs worse than this one.

From The Onion

Kindergartner Being Groomed For Line-Leader Position

BELLE MEADE, TN—Kindergarten teacher and mentor Mrs. Allen believes 6-year-old Gregory Hutter "has what it takes" for the coveted post.