Data Source

Levitt and Fryer on race and IQ

by on April 10, 2013 at 7:03 am in Data Source, Economics, Education | Permalink

From their April 2013 AER piece:

Analyzing these data, we find extremely small racial differences in mental functioning of children age 8 to 12 months.  Absent controls, the mean white infant outscores the mean black infant by 0.055 standard deviation units — only a sliver of the one-standard-deviation racial gap typically observed at older ages.  The raw scores for blacks are indistinguishable from Hispanics and Asians, who also slightly underperform whites.  Adding interviewer fixed effects and controls for the child’s age, gender, socioeconomic status (SES) and prenatal circumstances further compresses the observed racial differences.  With these covariates, we cannot reject equality in test scores across any of the racial/ethnic groups examined.

The piece is titled “Testing for Racial Differences in the Mental Ability of Young Children.”  Versions of the piece are here, but I believe the final version is not yet in jstor.

Note that to the extent you treat parental IQ as affecting the IQ of the child through environment, these results are consistent with a wide variety of accounts of racial gaps in IQ.  Still, there is no serious evidence, from these results, against the claim that the measured racial IQ gap is due to environment and environment alone.

188 comments

Sentences about household wealth (Cyprus fact of the day)

by on April 9, 2013 at 4:28 pm in Data Source | Permalink

On average, the wealthiest households are in Luxembourg, but Cyprus, which last month came close to a complete financial meltdown, was second.

That is from the eurozone.  And this:

Median net wealth is the lowest in the bloc’s paymaster, Germany (51,400 euros), less than a third of that in Italy (173,500 euros) or Spain (182,700 euros), due to the relatively low level of home ownership in Germany.

As I’ve said many times in the past, much about the future will depend on whether wealth taxation turns out to be politically feasible to a greater degree than at present.

47 comments

Undesirable trends in the labor force participation rate

by on April 8, 2013 at 4:25 pm in Data Source, Economics | Permalink

LabourForceRBCCM2-e1365451859304

From Cardiff Garcia, here is more.

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The hybrid educational model works

by on April 3, 2013 at 8:10 am in Books, Data Source, Education | Permalink

This is from the new William G. Bowen book, Higher Education in the Digital Age:

…we found no statistically significant differences in standard measures of learning outcomes (pass or completion rates, scores on common final exam questions, and results of a national test of statistical literacy) between students in the traditional classes and students in the hybrid-online format classes…This finding, in and of itself, is not different from the results of many other studies.  But it is important to emphasize that the relevant effect coefficients in this study have very small standard errors…what we have here are “quite precisely estimated zeros.”  That is, if there had in fact been pronounced differences in outcomes between traditional-format and hybrid-format groups, it is highly likely that we would have found them.

Note also that this finding holds across various subgroups of the basic student population, including students from families with incomes below 50k a year, first-generation college students, non-white students, and students with GPAs below 3.0.

The core report is here.

21 comments

What’s the best sentence ever formed?

by on April 3, 2013 at 7:23 am in Data Source, Education, Uncategorized | Permalink

That was the topic of a recent Quora forum (by the way may I officially announce that Quora seems to have succeeded?  Would it be so bad to spend less time with your Google Reader and more time browsing Quora?), and here was the top pick:

“I do not know where family doctors acquired illegibly perplexing handwriting; nevertheless, extraordinary pharmaceutical intellectuality, counterbalancing indecipherability, transcendentalizes intercommunications’ incomprehensibleness.”

(Dmitri Borgmann, Language on Vacation: An Olio of Orthographical Oddities. Scribner, 1965)

This is a ‘rhopalic’ sentence: A sentence or a line of poetry in which each word contains one letter or one syllable more than the previous word.

File under “Very good sentences’!  If I understand the Quora system correctly, that was from Ramnath Ragunathan.

Nishit Jain has the runner-up:

Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.

No, really. There’s a whole Wikipedia page on it – Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo

The sentence’s intended meaning becomes clearer when it’s understood that it uses the city of Buffalo, New York and the somewhat-uncommon verb “to buffalo” (meaning “to bully or intimidate”), and when the punctuation and grammar is expanded so that the sentence reads as follows: “Buffalo buffalo that Buffalo buffalo buffalo, buffalo Buffalo buffalo.” The meaning becomes even clearer when synonyms are used: “Buffalo-origin bison that other Buffalo bison intimidate, themselves bully Buffalo bison.”

The entire thread is worth reading, and in your spare time you can ponder why most of the best answers come from individuals with names from the subcontinent.  Here is the contribution of Veekas Shrivastava, listed as an elementary school chess player (retired):

A little grammar puzzle:

“that that is is that that is not is not that is it is it not”

Correctly punctuated: “That that is, is. That that is not, is not. That is it, is it not?”

Here is from Sugavanesh Balasubramanian:

“However, this valorous visitation of a by-gone vexation, stands vivified and has vowed to vanquish these venal and virulent vermin vanguarding vice and vouchsafing the violently vicious and voracious violation of volition.”

So there.

71 comments

The Flynn effect vs. population aging

by on March 31, 2013 at 4:12 pm in Data Source, Education, Science | Permalink

Here is some good news for you all on Easter Sunday, good news until 2042 that is:

Although lifespan changes in cognitive performance and Flynn effects have both been well documented, there has been little scientific focus to date on the net effect of these forces on cognition at the population level. Two major questions moving beyond this finding guided this study: (1) Does the Flynn effect indeed continue in the 2000s for older adults in a UK dataset (considering immediate recall, delayed recall, and verbal fluency)? (2) What are the net effects of population aging and cohort replacement on average cognitive level in the population for the abilities under consideration?

First, in line with the Flynn effect, we demonstrated continued cognitive improvements among successive cohorts of older adults. Second, projections based on different scenarios for cognitive cohort changes as well as demographic trends show that if the Flynn effect observed in recent years continues, it would offset the corresponding age-related cognitive decline for the cognitive abilities studied. In fact, if observed cohort effects should continue, our projections show improvements in cognitive functioning on a population level until 2042—in spite of population aging.

That is from Vegard Skirbekk, Marcin Stonawski, Eric Bonsang, and Ursula M. Staudinger, and one gated link is here.  Do any of you know of an ungated copy?

For the pointer I thank Michelle Dawson.

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American writing is now more emotional than British writing (big data for books)

by on March 29, 2013 at 1:54 pm in Books, Data Source | Permalink

From Alberto Acerbi, Vasileios Lampos, Philip Garnett, and R. Alexander Bentley:

Our results also support the popular notion that American authors express more emotion than the British. Somewhat surprisingly, this difference has apparently developed only since the 1960s, and as part of a more general stylistic differentiation in American versus British English, reflected similarly in content-free word frequencies. This relative increase of American mood word use roughly coincides with the increase of anti–social and narcissistic sentiments in U.S. popular song lyrics from 1980 to 2007, as evidenced by steady increases in angry/antisocial lyrics and in the percentage of first-person singular pronouns (e.g., I, me, mine), with a corresponding decrease in words indicating social interactions (e.g., mate, talk, child) over the same 27-year period.

And there is this:

As these findings appear to genuinely reflect changes in published language, a remaining question is whether word usage represents real behavior in a population, or possibly an absence of that behavior which is increasingly played out via literary fiction (or online discourse). It has been suggested, for example, that it was the suppression of desire in ordinary Elizabethan English life that increased demand for writing “obsessed with romance and sex”. So while it is easy to conclude that Americans have themselves become more ‘emotional’ over the past several decades, perhaps songs and books may not reflect the real population any more than catwalk models reflect the average body; the observed changes reflect the book market, rather than a direct change in American culture. We believe the changes do reflect changes in culture, however, because unlike lyrics of the top 10 songs, the book data are independent of book sales.

The full article is here, with other points of interest.  For instance of the major emotions coded for, disgust is the one least likely to show up in book writing.  I owe the pointer to someone or other on Twitter, but right now it is simply an open window on my computer, next to the Twitter window.

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Overall health inequality seems to be down

by on March 26, 2013 at 3:30 am in Data Source, Medicine | Permalink

The haves are those who enjoy great health into their 90s. The have-nots are those who suffer from serious health problems and do not live to see adulthood. As we pointed out in a recent study, among those Americans who were born in 1975, the unluckiest 1 percent died in infancy, while the luckiest 1 percent can expect to live to age 105 or longer. Now let’s fast forward to those born in 2012. The bottom percentile of this cohort can expect to survive until age 18. At the other end of the spectrum, the luckiest 1 percent can expect to live to age 108. That’s a much bigger gain in life expectancy among the have-nots than among the haves. Of course, life expectancy is but one measure of health and well-being, but understanding these trends offers a more complete picture than considering income alone.

These findings run counter to headlines noting a widening gap in health outcomes between different demographic groups. For example, a study led by Jay Olshansky of the University of Illinois at Chicago recently demonstrated that the gap in life expectancy between less educated and more educated Americans has widened considerably.

While studies like these are valuable in highlighting disparities between socio-economic groups, they do not tell us much about overall health inequality. That’s because most health inequality occurs within groups. In other words, if we look at a particular demographic group, the best outcomes for people in that group are dramatically different from the worst outcomes for people in the same group. These differences overwhelm any differences in average life expectancy across demographic groups. Thus, while inequality across some demographic groups has increased, it has fallen over the entire population. Overall, therefore, the health have-nots have made progress in catching up to the health haves.

That is from Benjamin Ho and Sita Nataraj Slavov.  I am open to counters on the data side, but so far this seems both a) true and b) rooftop-worthy.  I am reminded of Arnold Kling’s three axes of ideology; perhaps health care inequality attracts attention only when the victims are a group (the poor) who are part of some other narrative of oppression.

105 comments

Shout it from the Rooftops! Performance Pay for Teachers in India

by on March 22, 2013 at 7:26 am in Data Source, Economics, Education | Permalink

Several years ago I reported on a very large, randomized experiment (JSTOR) on teacher performance pay in India that showed that even modest incentives could significantly raise student achievement and do so not only in the incentivized subjects but also in other non-incentivized subjects, suggesting positive spillovers. The earlier paper looked at the first two years of the program. One of the authors, Karthik Muralidharan, now has a follow-up paper, showing what happens over 5 years. The results are impressive and important:

Students who had completed their entire five years of primary
school education under the program scored 0.54 and 0.35 standard deviations (SD) higher than
those in control schools in math and language tests respectively. These are large effects
corresponding to approximately 20 and 14 percentile point improvements at the median of a
normal distribution, and are larger than the effects found in most other education interventions in
developing countries (see Dhaliwal et al. 2011).

Second, the results suggest that these test score gains represent genuine additions to human
capital as opposed to reflecting only ‘teaching to the test’. Students in individual teacher
incentive schools score significantly better on both non-repeat as well as repeat questions; on
both multiple-choice and free-response questions; and on questions designed to test conceptual
understanding as well as questions that could be answered through rote learning. Most
importantly, these students also perform significantly better on subjects for which there were no
incentives – scoring 0.52 SD and 0.30 SD higher than students in control schools on tests in
science and social studies (though the bonuses were paid only for gains in math and language). There was also no differential attrition of students across treatment and control groups and no
evidence to suggest any adverse consequences of the programs.

…Finally, our estimates suggest that the individual teacher bonus program was
15-20 times more cost effective at raising test scores than the default ‘education quality
improvement’ policy of the Government of India, which is reducing class size from 40 to 30
students per teacher (Govt. of India, 2009).

In another important paper, written for the Government of India, Muralidharan summarizes the best research on public schools in developing countries. His conclusion is that there are demonstrably effective and feasible policies that could improve the public schools thereby increasing literacy and numeracy rates and raising the incomes of millions of people.

The generation entering Indian schools today is the largest that has ever, or for the foreseeable future, will ever enter Indian schools so the opportunity to raise educational quality for essentially the entire Indian workforce over the next several generations is truly immense.

30 comments

Might this generation have less wealth?

by on March 15, 2013 at 7:03 am in Data Source, Economics | Permalink

A new study from the Urban Institute finds that Ms. Brady and her peers up to roughly age 40 have accrued less wealth than their parents did at the same age, even as the average wealth of Americans has doubled over the last quarter-century.

Because wealth compounds over long periods of time — a dollar saved 10 years ago is worth much more than a dollar saved today — young adults probably face less secure futures for decades down the road, and even shakier retirements.

“In this country, the expectation is that every generation does better than the previous generation,” said Signe-Mary McKernan, an author of the study. “This is no longer the case. This generation might have less.”

That is from Annie Lowrey.  I would note that some of these “future benefits” will be consumed in the form of health care, but still I think this is far from an efficient (or just) outcome.

120 comments

Wage share of gdp in Middle East and North Africa

by on March 11, 2013 at 7:41 am in Current Affairs, Data Source, Economics | Permalink

wageshare

From Timothy Taylor, here is more.

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And yet the labor force participation rate is still falling

by on March 9, 2013 at 2:13 am in Current Affairs, Data Source, Economics | Permalink

laborforceparticipation

From Peter Coy, source here.  (And broken down by age here, I never find that disaggregation reassuring however, since the elderly are working more and the young less.)  Here are related comments and charts from Dylan Matthews.  Yet perhaps Felix Salmon has the clincher:

The number of multiple jobholders rose by 340,000 this month, to 7.26 million — a rise larger than the headline rise in payrolls. Which means that one way of looking at this report is to say that all of the new jobs created were second or third jobs, going to people who were already employed elsewhere. Meanwhile, the number of people unemployed for six months or longer went up by 89,000 people this month, to 4.8 million, and the average duration of unemployment also rose, to 36.9 weeks from 35.3 weeks.

Catherine Rampell discusses the rise of part-time work, very important stuff.  Here are relevant remarks by Pethoukis.  Here is more on the long-term unemployed.

By the way, my point is not to deny the “good news” aspects of the report, as summarized by Matthews and discussed elsewhere.  I would instead put it this way: we are recovering OK from the AD crisis, but the structural problems in the labor market are getting worse.  It’s becoming increasingly clear those structural problems were there all along and also that they are a big part of the real story.  On the AD side, mean-reversion really is taking hold, as it should and as is predicted by most of the best neo-Keynesian models.

50 comments

What is the consumer surplus from the internet?

by on March 8, 2013 at 11:41 am in Data Source, Economics, Web/Tech | Permalink

The Economist has an excellent survey article, here is one (not the only) estimate:

Yet another technique is to assign a value to the leisure time spent on the web. Erik Brynjolfsson and Joo Hee Oh of the Massachusetts Institute of Technology note that between 2002 and 2011, the amount of leisure time Americans spent on the internet rose from 3 to 5.8 hours per week. The authors conclude that in so far as consumers must have valued their time on the internet more than the alternatives, this increase must reflect a growing consumer surplus from the internet, which they value at $564 billion in 2011, or $2,600 per user. Had this growth in surplus been included in GDP, it would have raised economic growth since 2002 by 0.39 percentage points on average.

I would note one caution.  Consumer surplus per se does not make published gdp figures inaccurate for most purposes, since all goods and services yield consumer surplus to some extent.  One might argue, however, that the internet has higher than average consumer surplus, for purposes of thinking about human welfare.

25 comments

Facts about doctors

by on March 4, 2013 at 3:22 pm in Data Source, Medicine | Permalink

…new M.D.s per senior fell by about a third over the last three decades.

Much as I sometimes mistrust doctors, that is not good news.  And I find it sad how infrequently this number is discussed.  There is more from Bryan Caplan here.  And get this:

New male M.D.s per person are down by over 45%.

That is a sign of rising female prominence when it comes to educational success, but there is no good reason why the flow of male doctors should be falling so rapidly; it’s not as if men suddenly have lost the ability to doctor.

177 comments

Are we living in the early 19th century?

by on March 4, 2013 at 7:06 am in Data Source, Economics, History | Permalink

I frequently make this reference in talks, though I can’t recall having blogged it yet.

Here is one report from the front today:

Corporate earnings have risen at an annualized rate of 20.1 percent since the end of 2008, he said, but disposable income inched ahead by 1.4 percent annually over the same period, after adjusting for inflation.

“There hasn’t been a period in the last 50 years where these trends have been so pronounced,” Mr. Maki said.

If we turn to the industrial revolution, what do we see?  Relatively high productivity from “restructuring,” (machinery replacing labor) but relatively low productivity from innovation or total factor productivity.  Robert C. Allen, in his “Engels’ pause: Technical change, capital accumulation, and inequality in the British industrial revolution” (pdf, the final version is in Explorations in Economic History, 2009) estimates TFP from the time at about 0.69% a year, hardly a stunning number (the number runs in the 2%-3% range for the 1920s and 1930s) and actually that early number is close to what we are seeing today for TFP.

From 1780 to 1840, output per worker rose 46% and the real wage index rose by only about 12%, noting that none of these numbers are close to exact.  (Contra Ricardo, the share going to land is declining steadily and capital is capturing the gains.)  The significant real wage gains come after 1840 and — in my view — even more after 1870.  After 1830 TFP is growing at the higher rate of about 1% a year, still not impressive by the standards of the early 20th century however.

During the early 19th century, there is much creative ferment, but much less in terms of products which translate into gains in living standards for the average person.

By the way, you also have theorists — Malthus, Lauderdale, Chalmers, Attwood, and others — who thought the main problem was simply lack of aggregate demand, which Malthus called effectual demand.  They were absolutely right about part of the picture in the short run but missed most of the larger truths.

Eventually all of the creative ferment of the industrial revolution pays off in a big “whoosh,” but it takes many decades, depending on where you draw the starting line of course.  A look at the early 19th century is sobering, or should be, for anyone doing fiscal budgeting today.  But it is also optimistic in terms of the larger picture facing humanity over the longer run.

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