Category: Data Source

College students are working less hard, it seems

Philip Babcock and Mindy Marks report:

Using multiple datasets from different time periods, we document declines in academic time investment by full-time college students in the United States between 1961 and 2003. Full-time students allocated 40 hours per week toward class and studying in 1961, whereas by 2003 they were investing about 27 hours per week. Declines were extremely broad-based, and are not easily accounted for by framing effects, work or major choices, or compositional changes in students or schools. We conclude that there have been substantial changes over time in the quantity or manner of human capital production on college campuses.

An earlier, different and ungated version is here.  A closely related paper, by the same authors, is here.

Which Americans are “best off”?

I know that is a tricky concept, and I wouldn't personally use those words, but if you consult human development indices the answer is Asians living in New Jersey.  The standard is:

The index factors in life expectancy at birth, educational degree attainment among adults 25-years or older, school enrollment for people at least three years old and median annual gross personal earnings.

What does New Jersey do right?  How much of that is selection?:

Across the 50 states and the District of Columbia, Asian Americans were worst off in Louisiana. Their New Jersey counterparts lived an average of nine years longer and earned more than twice that of Asian Americans in Louisiana.

Overall Asian-American life expectancy is 86.6 years.  Here's a scary sentence:

Washington, D.C. offered the highest level of human development among whites.

African-Americans fare best in Maryland, which also may be a DC effect.  There is this too:

Latinos outlive whites, on average, by over four years, and in all but four states

The full blog post is here and for the pointer I thank DavidMWessel.

Tolerating male homosexuals lowers HIV

Andy Francis and Hugo Mialon, both at Emory, report their latest research:

We empirically investigate the effect of tolerance for gays on the spread of HIV in the United States. Using a state-level panel dataset spanning the mid-1970s to the mid-1990s, we find that tolerance is negatively associated with the HIV rate. We then investigate the causal mechanisms potentially underlying this relationship. We find evidence consistent with the theory that tolerance for homosexuals causes low-risk men to enter the pool of homosexual partners, as well as causes sexually active men to substitute away from underground, anonymous, and risky behaviors, both of which lower the HIV rate.

That piece has recently come out in the Journal of Health Economics.

How politically segregated are the networks of the internet?

For all the complaints you hear, internet reading is much less segregated than the networks of our work, family, and friends (all given formal measurements in the paper).  Jesse Shapiro and Matt Gentzkow report:

We use individual and aggregate data to ask how the Internet is changing the ideological segregation of the American electorate. Focusing on online news consumption, offline news consumption, and face-to-face social interactions, we define ideological segregation in each domain using standard indices from the literature on racial segregation. We find that ideological segregation of online news consumption is low in absolute terms, higher than the segregation of most offline news consumption, and significantly lower than the segregation of face-to-face interactions with neighbors, co-workers, or family members. We find no evidence that the Internet is becoming more segregated over time.

Here are some details:

The average Internet news consumer’s exposure to conservatives is 57 percent, slightly to the left of the US adult population. The average conservative’s exposure is 60.6 percent, similar to a person who gets all her news from usatoday.com. The average liberal’s exposure is 53.1 percent, similar to a person who gets all her news from cnn.com. The isolation index for the Internet is 7.5 percentage points, the difference between the average conservative’s exposure and the average liberal’s exposure.

News consumers with extremely high or low exposure are rare. A consumer who got news exclusively from nytimes.com would have a more liberal news diet than 95 percent of Internet news users, and a consumer who got news exclusively from foxnews.com would have a more conservative news diet than 99 percent of Internet news users.

…Visitors of extreme conservative sites such as rushlimbaugh.com and glennbeck.com are more likely than a typical online news reader to have visited nytimes.com.

This is one of the best papers on on-line media.

The gender gap in math is weak in Muslim countries

Moving to cross-country comparisons, we find earlier results linking the gender gap in math to measures of gender equality are sensitive to the inclusion of Muslim countries, where, in spite of women’s low status, there is little or no gender gap in math.

That is for students, not mathematicians, and it is from a new paper by Roland Fryer and Steve Levitt, hat tip goes to Chris Blattman.  Overall they conclude that the standard variables do not very well explain changes in the gender gap in math over time.

A non-gated version of the paper is here and it seems to be different.  Here is another version.

Is the VAT a money machine?

This is a very useful paper, full of facts and figures on VATs around the world.  Here is one bit:

As shown in the first column, all OECD members other than the U.S. have adopted the VAT over the last 30 years or so, beginning with France continuing through adoption by Australia in 2000. The (unweighted) average standard rate of VAT is about 17 percent, but with considerable variation. Within the EU, it varies between 15 percent (the minimum permissible under the union’s rules) in Luxembourg, and 25 percent (the maximum) in Denmark and Hungary. And several non–EU countries apply far lower standard rates than this, the most striking being the fi ve–percent rate in Japan. Most also apply a reduced rate to some commodities, with domestic zero–rating being quite widespread. The fourth column shows that revenue from the VAT is also typically substantial– averaging a little over seven percent of GDP–but again with considerable variation, from a high of over 12 percent of GDP in Iceland to a low of around 2.5 percent in Japan.

The authors — Michael Keen and Ben Lockwood — conclude that a VAT is a "weak" money machine in the sense that increases in a VAT are partially offset by declines in other tax rates.  They also note:

In a purely statistical sense, there is, thus, no strong evidence that the VAT has in itself caused the growth of government.

I saw this on Twitter somewhere, though now I forget whom to thank; sorry! [Update: It is probably "the wisdom of Garett Jones"]

Do daughters make you more conservative?

Dalton Conley and Emily Rauscher report:

Washington (2008) finds that, controlling for total number of children, each additional daughter makes a member of Congress more likely to vote liberally and attributes this finding to socialization. However, daughters’ influence could manifest differently for elite politicians and the general citizenry, thanks to the selection gradient particular to the political process. This study asks whether the proportion of female biological offspring affects political party identification. Using nationally-representative data from the General Social Survey, we find that female offspring induce more conservative political identification. We hypothesize that this results from the change in reproductive fitness strategy that daughters may evince.

I don't yet see an ungated copy, do you?  By the way, I applaud the authors for their "stones" in writing the last paragraph of the paper, such as:

The conservative emphasis on family, traditional values and gender roles, and prolife anti-abortion sentiments all stress investment in children – for both men and women. Conservative policies mirror the genetic interests of women, writ large. They attempt to promote paternal investment in offspring. Further, they stress investment in conceived offspring – “a bird in the hand is worth two in the bush.” In short, Conservative policies support the genetic fitness of women by capitalizing on each pregnancy, reducing male promiscuity, and increasing paternal investment in children. Such policies may impinge on the freedom of parents’ immediate offspring, but they increase the expected number of grandchildren via daughters.

I'm not sure that's true as stated, but it does deserve further debate.

Does incarceration make people black?

In a paper in Social Problems, Saperstein and Penner find that there is a surprising amount of variability in racial identification in the NLSY.  Some of this variation is due to error or other random factors but some of it also appears to be systematic.  In particular, the authors find that if someone has been incarcerated they are more likely to self-identify as black as well as to be independently identified as black.  As the authors put it

Results show that respondents who have been incarcerated are more
likely to identify and be seen as black, and less likely to identify
and be seen as white, regardless of how they were perceived or
identified previously. This suggests that race is not a fixed
characteristic of individuals but is flexible and continually negotiated
in everyday interactions.

Here is a key table.  In the first column is the respondent's self-identification, European or Black, in 1979.  Thus 95% of the people who identified as European in 1979 and who were not incarcerated between 1979 and 2002 identified themselves as White in 2002.  In other words, racial identification for the non-incarcerated was quite stable.  But only 80% of the people who identified as European in 1979 and who were incarcerated between 1979 and 2002 identified themselves as White in 2002.  Thus incarceration appears to affect how people identify themselves.

The result is surprising at first but makes sense once one sees it as a natural extension of Akerlof and Kranton's work on identity.

RaceID

Note that there are some issues with the data since the precise
questions asked and options given changed over time (hence the change
from "European descent" to "White")–nevertheless, the differences
conditioning on incarceration appear to be robust–but see the paper
for more.

Hat tip Gabriel Rossman.

The iPad

Could this be the medium through which the fabled convergence finally occurs?

Most of all, think of it as a substitute for your TV.

It has the all-important quality of allowing you to bend your head and body as you wish (more or less), as you use it.  By bringing it closer or further, you control the "real size" of the iPad, so don't fixate on whether it appears "too big" or "too small."

The pages turn faster than those of Kindle.  The other functions are also extremely quick and the battery feels eternal.

So far my main complaint is how it uses "auto-correct" to turn "gmu" into "gum."

While I will bring it on some trips, most of all it feels too valuable to take very far from the house.

On YouTube I watched Chet Atkins, Sonny Rollins, and Angela Hewitt.

Note all the categories on this short post!

China facts of the day

As far as China’s involvement with the rest of the world goes, the real story since the worst of the crisis is not China’s recovering exports but China’s strong imports. The forthcoming trade release – interestingly due a few days before the Treasury report – is likely to demonstrate enormous import growth again, absolutely and relative to exports. This is seen not just in Chinese data, but in those from many other important trading nations. Indeed, quite remarkably, Germany’s trade with China is showing such strong growth that by spring next year, on current trends, it might exceed that with France. China last year reported a current account surplus of 5.8 per cent of GDP, significantly lower than apparently assumed as the current level by many people in Washington. In 2010, it could be closer to 3 per cent – incidentally below the 4 per cent level deemed as “equilibrium” by the Peterson Institute for International Economics.

There is more here.  Resist the call of those who would have us start a trade war with China.  Some of this is tasteless and stupid, but other parts are right on the mark.

Haiti fact of the day

Nearly 17 percent of Haiti's civil servants died in the disaster, including many senior managers…

Most likely these were the people most likely to be inside of relatively substantial buildings.  It's also a reflection of how much Haitian government was concentrated in Port-au-Prince.  Did you know that the U.S. occupation of 1915-1934 encouraged this centralization, if only to make the country easier to rule?  The full story is here.