Month: April 2007

How many children should you have?

From a private point of view, only one:

In comparing identical twins, Kohler found that mothers with one child are about 20 percent happier than their childless counterparts; and while fathers’ happiness gains are smaller, men enjoy an almost 75 percent larger happiness boost from a firstborn son than from a firstborn daughter [TC: remember the result that fathers with sons are less likely to leave?].  The first child’s sex doesn’t matter to mothers, perhaps because women are better than men at enjoying the company of both girls and boys, Kohler speculates.

Interestingly, second and third children don’t add to parents’ happiness at all.  In fact, these additional children seem to make mothers less happy than mothers with only one child–though still happier than women with no children.

"If you want to maximize your subjective well-being, you should stop at one child," concludes Kohler, adding that people probably have additional children either for the benefit of the firstborn or because they reason that if the first child made them happy, the second one will, too.       

Here is the longer story.  See this paper.  Here is the researcher’s home page

I am hardly an expert in this area, but I find the logic appealing.  One kid is quite able to fill your time and thoughts.  I call this the "parent as empty vessel" model.  The argument for more than one kid, in this view, would rest on risk-aversion and the chance that one kid might die or not work out so well.

Note the contrast between Kohler with Bryan Caplan’s theory that you should have more kids now than you want, so you may enjoy them when you are old.  At that point in time, no single kid "fills the empty vessel" and so more of them are needed.

I believe that men enjoy children more than women do, as they are less stressed by worry.  Whether men want children more is a different question [this last sentence has been altered from a previous version.]

The pointer is from the still totally awesome

Reviewing Landsburg’s Errors

In the Armchair Economist, Steven Landsburg argues that the people who read his book are likely to find that it wasn’t as good as they expected.  The logic is impeccable – people who over-estimate the value of the Armchair Economist are more likely to buy it and thus discover their over-estimation (sadly, under-estimators never learn of their mistake).  Nevertheless, despite the logic, I and many others discovered that Landsburg was wrong.  The Armchair Economist and every Landsburg book exceed expectations. 

Landsburg is back with More S-ex is Safer S-ex, and another error.  This time Landsburg suggests that writing his book was socially destructive.  Again, the logic is impeccable – a good book creates a lot less value than its price because to a large extent it displaces the second best book which was almost as good.  Authors however are paid based on price and not on social value and thus write too many books.  And yet, I must again disagree for Landsburg’s new book is a treasure.  There is something to learn on almost every page.

Here’s one idea I learned.  In the debate over the economics of global warming the correct discount rate to apply to future generations is a key variable with those arguing that we should do something now, implicitly (and explicitly) arguing for a low discount rate.  But if we count future generations highly we ought also to be in favor of reforming social security.  Investing social security in the stock market "royally screws" current retirees but increases the savings rate which will be benefit future generations.  Thus, a low discount rate ought to weigh in favor of doing something about global warming and investing social security funds in the stock market.  Not many people come out consistent on these grounds (I think Brad DeLong is one of the few.)  I know, I don’t but Landsburg has got me thinking.

The Patriarchy at Work

Many studies have shown that women are
under-represented in tenured ranks in the sciences. We evaluate
whether gender differences in the likelihood of obtaining a
tenure track job, promotion to tenure, and promotion to full
professor explain these facts using the 1973-2001 Survey of
Doctorate Recipients. We find that women are less likely to take
tenure track positions in science, but the gender gap is entirely
explained by fertility decisions. We find that in science
overall, there is no gender difference in promotion to tenure or
full professor after controlling for demographic, family,
employer and productivity covariates and that in many cases,
there is no gender difference in promotion to tenure or full
professor even without controlling for covariates. However,
family characteristics have different impacts on women’s and
men’s promotion probabilities. Single women do better at each
stage than single men, although this might be due to selection.
Children make it less likely that women in science will advance
up the academic job ladder beyond their early post-doctorate
years, while both marriage and children increase men’s likelihood
of advancing.

From "Does Science Promote Women? Evidence from Academia 1973-2001".

Addendum: Tyler linked to an earlier version of this paper but if I forgot then probably so did you so here it is again.

How has income volatility evolved?

I’ve had many people asking me whether Jacob Hacker’s results about "the great risk shift" hold up.  The CBO weighs in:

Since 1980, there has been little change in earnings variability for both men and women.  There is some evidence that, between 1960 and 1980, earnings variability increased for men but was offset by a decrease for women.  Those findings are consistent with most existing studies of the topic that use publicly available survey data, which tend to find higher levels of earnings variability for men in the 1980s and 1990s relative to the 1970s, but little change since around 1980.

Here is the paper.  I’ll read through it soon, and report back if my deeper impression runs in the other direction.  If you know of relevant defenses of Hacker, please do leave them in the comments.  I’d like to get to the bottom of this.

Which cities fought the 1918 pandemic best?

Those that acted early, here is a new and noteworthy paper.

What worked: Early school, church, and theater closures.  The estimate for banning public gatherings depends on the test used.

What didn’t work: Closing dance halls, isolating flu cases, banning public funerals, and making influenza notifiable.

Early-acting cities were especially effective at stopping many casualties at the first flu wave, rather than being devastated by later waves as well.  Letting down one’s guard too early was a common problem.

The authors stress that this study used only 17 cities with highly correlated explanatory variables.  Still, in a case like this some chance at knowledge is better than no knowledge.  Here is a related paper. Here is a New York Times discussion of the results.

Public Opinion and War

Political scientist Scott Althaus was here last week and had a lot of interesting things to say about war and public opinion.  Here is one tidbit.  The public’s opinion of past wars improves as a new war approaches.  Thus, after Vietnam most people thought the war was a mistake and this held true for decades until the beginning of the Iraq war when the opinion of war in Vietnam suddenly improved!  Even more dramatically, a majority of people thought that World War I was a mistake until World War II approached when the percentage thinking it was a good war doubled.  This is especially perverse in that any rational response has got to see WWI as a bigger mistake the more probable is WWII. 

Althaus also shows, in Priming Patriots, that the intensity of new coverage typically increases support for war – regardless of whether the coverage is negative or positive.  Until negative news becomes overwhelming and long-lasting, more coverage simply rallies the martial spirit, encourages solidarity and solidifies support for the war.  This explains a lot.

What checks on democracy are required to deal with the irrationality of public opinion about war? 

Edward Cumberbatch

Eddie wants to continue improving the quality of his performances but does not envision himself as a full-time professional singer.  A life on the road, a continuity of auditions for roles do not fit his preferred ordered lifestyle.  However, should an opportunity arise to work with a famed Music Company he would welcome the experience.

Edward Cumberbatch is a national treasure of Trinidad.  I heard Eddie in concert about ten years ago, in a high school auditorium in Port of Spain.  His sister played piano.  I was blown away by Eddie’s voice and his stage presence.  He could sing anything from gospel (his origins) to classical to swing.  His creole version of the love duet in Donizetti’s The Elixir of Love remains one of the musical highlights of my life.  At the time, Eddie seemed like a more compelling artist than Domingo, Bryn Terfel, or any of the other voices I have heard in concert.  But mostly he sings in his church choir for no remuneration or even fame.

Joshua Bell’s Washington Metro performance has got me thinking more about Eddie.  Is Eddie an undiscovered vocal genius?  An unreliable charismatic who swindles the ears of lesser mortals?  An eccentric who simply refuses to step into his rightful place on the global stage?  A beneficiary from low expectations, who would choke if given a recital at the Met?  A wise man who knows where true happiness lies?  Here is more on Eddie.

I was shocked when I read in the program notes that Eddie also has a Ph.d. in Physics from Indiana University.

I continue to believe in him.  Can I go through life not doing more about Eddie?

Addendum: Read this article on how social forces influence our evaluation of music.

The violence of American youth

I’ll let the firearms debate be played out elsewhere.  What other factors might matter?

American youth have different attitudes toward life and death than do
youth in other countries.  The authors cited a World Health Organization
study, which reported that American youth are more likely to believe
it’s appropriate to kill to protect their property than were youth in
Estonia, Finland, Romania, and Russia.  Similarly, the cited study noted
reports that adolescents in the United States are more likely to
approve of war than were youth in any of those countries.

Here is more.  Here is the U.S. trend over time, plus a comparison with Europe.  I see weaker social and family constraints, whatever their other benefits, as having dangerous effects on the psychotic outliers.

The good news?  School-associated homicides are less than one percent of all homicides involving students.  And this:

…trends throughout the 1990s show that the number of school homicides
has been declining.  Yet within this overall trend, homicides involving
more than one victim appear to have been increasing.

One politically incorrect interpretation is simply to note that American youth are becoming more ambitious and more "productive," not just in hi-tech.  Note also:

…the overall risk of violence and injury at school has not changed substantially over the past 20 years…

Here is an article which suggests the U.S. rate of youth violence is not so out of the ordinary, although it does take different and sometimes larger-scale forms.  Here is a more pessimistic (but more statistically selective) picture.  Here are further international comparisons.

What are the French good at?

“The French government has always been very good at making things where government support is critical,” like trains, nuclear power plants and airplanes, Mr. [Joel] Mokyr says.  “But the French are not terribly good at creating Googles or Microsofts, where private action is central.”

The French engineering company, Alstom, after all, is the world market leader in high-speed trains.  But a well-informed person would be hard-pressed to name a leading French information technology company.  Indeed, many of France’s best computer brains work in Silicon Valley.  These Franco-geeks, who number in the thousands, even have two associations, SiliconFrench and DBF.

“The French business system is constraining for individuals while supportive of scientists and engineers working on large, rigid systems that actually benefit from top-down decisions and slow change,” says Jean-Louis Gassée, a former Apple executive who helped organize DBF and is a partner at Allegis Capital in Palo Alto, Calif.

Here is more.  Looking toward culture, the French are relatively strong in cinema and contemporary classical music, but weak in painting and rock and roll.  Contemporary fiction you could argue either way, though I incline toward the negative.  I am not sure if these patterns fit into the broader thesis above, though perhaps health care would.

Markets in everything, Roman edition

One infamous auction during Roman times is described by Edward Gibbon in his Decline and Fall of the Roman Empire (1776).  When the Praetorian Guard killed the Roman emperor Pertinax on March 28, 193 A.D., they sold the Roman Empire itself to the highest bidder, the wealthy senator Didius Julianus, who "rose at once to the sum of six thousand two hundred and fifty drachms, or upwards of two hundred pounds sterling" per man…The new emperor lasted only two months, but did manage to strike some very handsome coins.

That is from the new Snipers, Shills, and Sharks: Ebay and Human Behavior, by Ken Steiglitz.  Here is the book’s home page.  Here is more background on the Roman auction.

The tax break for employer-provided health insurance

Remember when I wrote?

…how can a simple relative price, whether a distortion or not, corrupt the cost control practices of an entire industry?  And if government provision of health care is ineffective and costly, isn’t there a positive externality from the purchase of private health insurance?

The tax break for employer-provided insurance is, more or less, thirty percent.  Therefore the cost burdens of employer-supplied health care should not exceed that same thirty percent.  Have you noticed that current problems come in the form of cost escalation at high ongoing rates, and not just from a one-time cost bump upwards? 

If you think the tax break is behind the spiral of rising costs, you need only wait.  Once the sum total of those unnecessary costs exceeds thirty percent, the tax subsidy won’t be worth it, we’ll move to a more rational system, and all will be well, more or less.

That hardly seems believable. 

Consider an analogy with food.  Say my restaurant expenditures were subsidized by thirty percent (remember the tax deductible business lunch?).  They might put too much on my plate, and they’ll start overcharging me.  Maybe.  But once the initial adjustment occurs, it won’t lead to 5-10 percent cost escalation for meals each year.  And if it did, in a few years’ time I would simply switch to the unsubsidized meal sector, thus checking how bad the problem could get.

Addendum: See also Becker and Posner today.

The Rise, Fall, and Rise Again of Privateers

In August 1812, the Hopewell, a 346-ton ship laden with sugar, molasses, cotton, coffee, and cocoa, set sail from the Dutch colony of Surinam. Her captain was pleased because he reckoned that in London the cargo would sell for £40,000–the equivalent of at least several million dollars in today’s economy. The Hopewell carried fourteen guns and a crew of twenty-five, and for protection she sailed in a squadron of five other vessels. It was difficult, however, to keep a squadron together in the vast expanse of the Atlantic Ocean, and on August 13 the Hopewell became separated from her sisters.

    Two days later her crew spotted another ship, armed and approaching rapidly…

That’s the opening of my latest paper, The Rise, Fall, and Rise Again of Privateers.

Hat tip to Jesse Walker at Hit and Run and Instapundit both of whom spotted this before me!