Results for “Tests” 772 found
Hail Joseph Lancaster!
And for that matter hail Seth Weidman:
It was a classic case of supply and demand.
Entering his senior year at Pittsburgh Allderdice High School, Seth Weidman felt there was demand for an Advanced Placement economics class.
So he decided to supply one.
At least one night a week for nine months, Seth taught college-level economics to a group of his fellow Allderdice students, traveling from living room to living room with his dry-erase board in tow.
Fueled by Doritos, pretzels and the occasional homemade tiramisu, Seth’s students in the "Weidman School of Economics" numbered 18, with nine of them eventually taking at least one of the two AP economics tests offered.
Thus far, the results have been spectacular. The students took 12 total tests, and of the eight scores that have come in this month, six are 5’s — the highest possible on a scale of 1 to 5 — and two are 4’s.
Greg Mankiw and Aplia appear in the story as well. Seth loves Hayek’s Road to Serfdom: ""It made me see that economics isn’t just about a bunch of guys sitting on CNBC," he said. "It’s more about incentives. It gives you a cool perspective to understand the world."
Here is the full story. Seth will be attending the University of Chicago next year. Here is material on Joseph Lancaster and I thank Eric Crampton for the pointer.
Life among the liquidity constrained
This paper tests the hypothesis that the timing of welfare payments
affects criminal activity. Analysis of daily reported incidents of
major crimes in twelve U.S. cities reveals an increase in crime over
the course of monthly welfare payment cycles. This increase reflects an
increase in crimes that are likely to have a direct financial
motivation like burglary, larceny-theft, motor vehicle theft, and
robbery, as opposed to other kinds of crime like arson, assault,
homicide, and rape. Temporal patterns in crime are observed in
jurisdictions in which disbursements are focused at the beginning of
monthly welfare payment cycles and not in jurisdictions in which
disbursements are relatively more staggered.
Here is the link, here are non-gated versions.
Had I mentioned…?
That Tokyo is the best food city in the world? That’s by an order of magnitude; Paris and others aren’t close. At this point my best guess is that Osaka is number two.
I thank Yan Li for the pointer to the link, which is interesting on another topic as well. We visited a quite amazing toilet shop here, which was impressive most of all for its seriousness, not just for its product. It was I believe on the 26th floor (L-Building, Shinjuku), so there is no walk-in trade for them. They play stormy Beethoven and offer talking toilets, toilets that perform lab tests on your ****, and toilets that can be programmed to do things I hadn’t even thought of before.
CSI on Trial
…to judge by the most
comprehensive study on the reliability of forensic evidence to date,
the error rate is more than 10% in five categories of analysis,
including fiber, paint and body fluids. …DNA
and fingerprints are more reliable but still not foolproof….a 2005 study in the Journal of Criminal Law & Criminology
suggests a fingerprint false-positive rate a bit below 1%, a widely
read 2006 experiment shows an alarming 4% false-positive rate.How can we preserve the
usefulness of forensic evidence while protecting the public when it
breaks down? The core problem with the forensic system is monopoly.
Once evidence goes to one lab, it is rarely examined by any other. That
needs to change. Each jurisdiction should
include several competing labs. …This procedure may seem like a waste. But such checks would save
taxpayer money. Extra tests are inexpensive compared to the cost of
error, including the cost of incarcerating the wrongfully convicted….Other reforms should include
making labs independent of law enforcement and a requirement for blind
testing. When crime labs are part of the police department, some
forensic experts make mistakes out of an unconscious desire to help
their "clients," the police and prosecution. Independence and blind
testing prevent that.
That’s forensics expert Roger Koppl writing in Forbes. If anything I think Koppl is being kind to CSI. Take bullet lead analysis a procedure used by the FBI for decades that turns out to have no scientific validity whatsoever.
Full Disclosure: Koppl’s op-ed is based on a paper in a book called Law Without Romance edited by Ed Lopez to be published by Independent Institute where I am director of research.
Why we shouldn’t boycott the Olympics in any way
A wheelchair-bound Chinese torch bearer has rocketed to national fame after fending off protesters in Paris, becoming a symbol of China’s defiance of global demonstrations backing Tibet.
Jin Jing, a 27 year-old amputee and Paralympic fencer has been called the "angel in a wheelchair" and is being celebrated by television chat shows, newspapers and online musical videos after fiercely defending the Olympic torch during the Paris leg of the troubled international relay.
Protesters denouncing Chinese policy in Tibet threw themselves at Jin. Most were wrestled away by police but at least one reached her wheelchair and tried to wrench the torch away. Jin clung tenaciously to what has become a controversial icon of the Beijing Olympic Games until her attacker was pulled off. Her look of fierce determination as she shielded the torch, captured in snapshots of the scene, has now spread throughout China, inflaming simmering public anger at the protests. "I thought we had lost in France, but seeing the young disabled torch bearer Jin Jing’s radiant smile of conviction, I know in France we did not lose, we won!" said one of tens of thousands of Internet postings about the incident.
Here is the story. Here are further ramifications and don’t worry they’ll be happy to give up their coal factories too.
Johannes Fedderke and the importance of good governance
File him in the category underappreciated economists. Does good governance matter for growth? Could there be a more important question for economists? The standard cross-sectional growth tests do not show much of a robust effect. But Johannes, along with co-authors Robert Klitgaard and Kamil Akramov, has a 150-page paper showing that if you take all the relevant heterogeneities into account yes, Adam Smith and Doug North were right after all.
Or do you prefer simple regressions which meet the eyeball test?
Here is the full paper. Here is Johannes’s long paper on South African economic history.
School Choice: The Findings
This new Cato book is a good introduction to the empirical literature on vouchers and charter schools. For my taste it places too much weight on standardized tests, but admittedly that is the main way to compare educational results over time or across countries. I believe the lax nature of government schooling in the U.S. often leaves the upper tail of the distribution free to dream and create, but I would not wish to push that as an argument against vouchers. If you’re interested in bad arguments against vouchers, and their rebuttals, Megan McArdle offers a long post.
Was the Indian caste system efficient?
A new paper looks at some of the efficiency properties of castes:
The caste system in India has been dated to approximately 1000 B.C. and still affects the lives of a billion people in South Asia. The persistence of this system of social stratification for 3000 years of changing economic and social environments is puzzling. This paper formalizes a model of the caste system to better understand the institution and the reasons for its persistence. It argues that the caste system provided a tool for contract enforcement and facilitated trade in services, giving an economic reason for its persistence. A caste is modeled as an information-sharing institution, which enforces collective action. Trade is modeled as a version of the one-sided prisoner’s dilemma game, where the consumer has an opportunity to default. Consumers who default on a member of a caste are punished by denying them services produced in the caste. Various features of the caste system like occupational specialization by caste, a purity scale, and a hierarchy of castes are shown to be equilibrium outcomes that improve the efficiency of contract enforcement. The implications of the model are tested empirically using unique census data from Cochin (1875), Tirunelveli (1823) and Mysore (1941).
In other words, other caste members enforce norms on you and if you don’t follow them you are kicked out and you cannot easily join another caste. Sounds like my idea of fun. I have a few points:
1. No way should this paper spend so much time on a formal model.
2. The tests proffered on p.36 are related only tangentially to the paper’s main propositions.
3. When it comes to normative issues, the author can do no better than to write: "This should not be interpreted as saying that the case system was free of inefficiencies." And that comes only on p.46. Ha!
4. The paper commits the fallacies of excess functionalism.
5. Virtually any destructive institution which keeps economic transactions on a smaller scale may make contract enforcement "easier" in some regards.
6. This is nonetheless interesting work, and many more people should do research on this and related topics. But in terms of emphasis this paper is way off base.
The pointer is from New Economist blog, which offers related links. Readers, are any of you willing to defend the caste system, if only in part, on economic grounds?
The New Invisible Competitors
That is the title of my piece in the new Wilson Quarterly, not on-line anytime soon and yes you should subscribe. The piece looks at how people emotionally respond to the move from neighborhood, face-to-face competition to competition at a distance, or what I call invisible competition. Some people will fare better in this new environment than others; for instance people who rely on adrenalin to compete will find it harder to motivate themselves in this new and more impersonal environment:
The greatest gains in this new world are likely to go to people who are methodical planners or who love the game for its own sake. Some people plot their competitive strategies far in advance. These planners–be they crazy or just highly productive–don’t need anyone breathing down their necks, and indeed they often work best alone or in very small groups. Bill Gates is a classic example. Planners’ behavior may manifest itself in very competitive forms, but their underlying psychology is often not very rivalrous at all. They are ordering their own realities, usually for their individual psychological reasons, rather than acting out of a desire to trounce the competition. Early risers will also be favored. These people enjoy being first in line, or first to use a new idea, for its own sake.
Of course many of us miss face to face competition, so we try to recreate it in trivial ways, sometimes using our children:
As the concrete manifestations of the more important contests of love and business vanish, we recreate up-close rivalry to make our lives feel more real. I suspect that this helps explain the growing appetite for televised athletics and organized sports for children as well as the vogue for reality TV series such as Survivor and American Idol, eating contests, and even spelling bees. Because children are a cheap labor supply and willing to engage in all sorts of behavior for a chance at a prize or parental approval, they often serve as the vehicle for parents who seek to live out their desire for head-to-head competition vicariously. Spelling, for example, does not interest many people (who sits around practicing?), but bees exemplify the competitive spirit in action. The challenge to spell autochthonous, panmyelopathy, or warison will bring one kid to tears and another to triumph.
Oomph v. Statistical Significance
For those after the full debate, see:
- McCloskey and Ziliak, "The Standard Error of Regressions," Journal of Economic Literature 1996.
- Ziliak and McCloskey, "Size Matters: The Standard Error of Regressions in the American Economic Review," Journal of Socio-Economics 2004.
- Hoover and Siegler, "Sound and Fury: McCloskey and Significance Testing in Economics," Journal of Economic Methodology, 2008.
- McCloskey and Ziliak, "Signifying Nothing: Reply to Hoover and Siegler."
McCloskey has been making this point for some time, and a longer list of papers is available here, including several shorter (yet unsurprisingly persuasive) pieces.
What is Intelligence?: Beyond the Flynn Effect
That is the new book by James R. Flynn. He suggests the following:
Today we have no difficulty freeing logic from concrete referents and reasoning about purely hypothetical situations. People were not always thus.
In other words, people in earlier times really were stupider when it came to abstract thought, but this was primarily for environmental reasons. These people also had more daily, practical skills, again for reasons of practice. We in contrast receive daily workouts with hypotheticals, rapidly moving images, and spatial reasoning. So Flynn is suggesting that IQ isn’t more multi-dimensional than it may seem. The Flynn Effect gains are in fact concentrated in the most spatial and abstract versions of IQ tests.
Flynn summarizes the "Dickens-Flynn" model, through which environment and IQ interact in multiplicative fashion. Smart people seek out environments which make them even smarter, and this helps reconcile the cross-sectional IQ data (adoption doesn’t change IQ so much) with the time series of increasingly higher IQ scores (environments are changing for everybody). This reconciliation was fuzzy to me, but I took Flynn to be claiming that separated identical twins will reimpose common environmental forces on themselves, thus keeping their IQs in relatively close long-run synch. I still don’t understand what kind of test (might it contrast permanent vs. temporary environmental shocks?) might falsify the Dickens-Flynn model.
Flynn also argues that the Chinese in America attained high levels of achievement before
above-average IQs.
This book doesn’t tie up all the loose ends, and it could have been written in a more organized fashion. Still it is one of the more interesting volumes of the year.
Addendum: I have long thought that the Germanic "Hausmusik" tradition was responsible for producing so many great composers in one relatively short period of time. Flynn’s book offers (unintended) hints about why it is so hard to reproduce the cultural blossomings of times past, and also why future creations will seem baffling to the old fogies.
The Fed’s Dirty Laundry and Yours
Not content to kill people with CAFE standards the Federal government is now messing up our laundry. So called "energy-efficiency" standards have severely reduced the cleaning ability of new laundry marchines. Who says? Here is Consumer Reports:
Not so long ago you could count on most washers to get your clothes
very clean. Not anymore. Our latest tests found huge performance
differences among machines. Some left our stain-soaked swatches nearly
as dirty as they were before washing. For best results, you’ll have to
spend $900 or more. (italics added)What
happened? As of January, the U.S. Department of Energy has required
washers to use 21 percent less energy, a goal we wholeheartedly
support. But our tests have found that traditional top-loaders, those
with the familiar center-post agitators, are having a tough time
wringing out those savings without sacrificing cleaning ability, the
main reason you buy a washer.
I too support the goal of having washers use 21 percent less energy. Hell, I support the goal of having washers use no energy at all. Let’s pass a law.
Energy efficiency sounds so nice. Who could be against efficiency? Tradeofs, however, cannot be avoided. Thus, energy-efficiency really means that the government is going to choose how white your shirts are gonna be.
Ironically, the law could well reduce cleanliness and increase energy use. If the new washers are as bad as Consumer Reports say they are people will just start to wash everything twice.
Addendum 1: Prominent members of a certain political party often promote the theory that "if we make them build it, the savings will come"
but, as we all know, ignoring tradeoffs is a sure sign of discredited crackpot economics.
Addendum 2: CEI suggests you email some virtual underwear to the Secretary of Energy in protest.
A Farewell to Alms, pp.1-112
1. Did hunter-gatherers really have living standards as high as people in 18th century England? By focusing on the long run, Clark neglects the pains of equilibration. Hunter-gatherers who survived to 30 maybe had decent lives, but population was very low. It was kept low, in part, by lots of brutal and painful death. We can’t just focus on the steady-state conditions in making welfare comparisons. Modern research is also discovering that primitive societies have very high levels of war and violent death; if we’re playing time travel games, I’m opting for 1800, and not just to have a chance of hearing Haydn. I’ll also take modern Tanzania over the hunter-gatherers, in a heartbeat, contra what Clark implies.
2. Why should we aggregate income comparisons by country (or the whole world) rather than by city? World history looks very different if we do the latter. Aren’t most countries relatively recent inventions anyway? More generally, I would like a more disaggregated look at the data. Big chunks of the urbanized human population — pre 1800 — seem to have violated Malthusian precepts for centuries on end. "Stadtluft macht frei" was the old German saying.
3. How long is the long run? This is one of my biggest questions about the work and about Malthusian predictions more generally. Are we just comparing 30,000 B.C. to 1800 A.D.? If so, we have only two data points. If we look at times in between, there is much more scope for non-Malthusian results, even if they hold for "only centuries."
4. Violent conflict and predation are not given enough (any?) importance. Cities that avoid violent conflict do pretty well. Admittedly, violence is itself endogenous to Malthusian considerations, but I’m not going to reduce war to population pressures (and certainly Clark never tries to.) Isn’t part of the historical inability to boost long-run living standards simply the result of recurring wars and depredations? 17th century European history, among other times, shows just how much war matters.
5. Should I reject the Julian Simon model I grew up with? In that view there are increasing returns to scale within cities, where people usually don’t starve. The countryside languishes in poor countries, in part because it is underpopulated. Rather than having a "one population model" with an aggregate "n," labor markets are local. The "plagued by diseconomies of scale rural folk" cannot sufficiently connect with the "economies of scale urban sophisticates," mostly because of bad institutions and backward infrastructure. And the cities prove unable to protect themselves against all ongoing predations. Doesn’t that model fit the data too, and fit the disaggregated and shorter-run data better?
6. I can’t find the single place where Clark directly tests the Malthusian model. I fear he will regard this observation as unfair, since there is argumentation and data of some kind on virtually every page. But I still am not satisfied. I see lots of evidence for "history shows mean-reversion and population pressures are one factor affecting wages." It is harder to find a) what "best alternative" the Malthusian model is being tested against, b) what evidence would adjudicate between models, c) what is the short-run claim about the response of population to real wages, and d) what in history are the "hard cases" for the Malthusian model and how does Clark handle them?
7. Charles Kenny argues that the Malthusian model does not explain observed short-run dynamics for population and real wages. I don’t regard this piece as a refutation of Clark by any means, but the evidence on how well real wages predict population growth seems to me murky rather than decisively in Clark’s favor. There’s just not a single, simple model at work here.
If you are coming to the book blind, here is a short piece by Clark. Here is my earlier column on the manuscript. Here is a survey paper on the Industrial Revolution and the Malthusian trap. Here is more good background. Peter Lindert considers how much real wages predict population growth in British history. Read this too.
What do you all think?
Surprising evidence on the Flynn Effect
1. Non-verbal IQ has risen more rapidly than has verbal IQ.
2. Performance gains are smallest on the most culturally specific tests, and largest on the most abstract tests.
3. Performance gains, as they occur over time, are roughly constant for all age groups.
4. Problem-solving abilities have seen the biggest performance gains.
5. Gains on the "Ravens" test started occurring before the TV era, much less the computer game era.
#3 is perhaps the biggest surprise to me, as it contradicts most of the obvious explanations for the Flynn effect.
Those results are summed up in the very interesting "The Flynn effect and its relevance to Neuropsychology," by Merrill Hiscock, Journal of Clinical and Experimental Neuropsychology, 2007. Here is Andrew Gelman’s post on that paper.
Hiscock puts it well: "..the Flynn effect constitutes a compelling example of large between-group IQ differences [across generations] that are completely environmental."
What accounts for reading speed?
To knock out sentence context, they changed word order (e.g.
“Contribute others. The of Reading measured”). To knock out whole word
recognition, they alternated capital and lower case (e.g. “ThIs tExT
AlTeRnAtEs iN CaSe”). And to knock out letter-by-letter decoding, they
substituted letters in such a way that word shape was maintained (e.g.
“Reading” becomes “Pcedirg”).Letter decoding was found to
account for 62 per cent of reading speed; whole word recognition 16 per
cent; and sentence context 22 per cent.
I wasn’t there for the tests, but I believe that is measuring reading speed at margins other than what we find on the printed page. "Knowing what is coming" is in my view most important for reading fast. (I like to say "It took me 45 years to read that book." If you think you "just started" the book in your hands right now, you are failing to understand the proper marginal unit.)
I find that when I try to read graphic novels, I am not a very fast reader at all. My eyes get confused from not knowing where the next block of text will appear.
I am also struck by an incidental remark toward the end of the article; we are getting closer to the truth:
…among the faster readers, predicting words from sentence context made a
bigger contribution to reading speed than among the slower readers.
Addendum: Here is my previous post on reading speed.