Depressing that this is news

This headline is about the latest game for one of the best US soccer players playing abroad:

Beasley Booed But Not Racially Abused By Red Star Fans

Studying pays off in college

Todd and Ralph Stinebrickner find that being assigned a roommate with a video game system reduces first semester GPA by 0.2 points! OLS estimates show that an extra hour/day of studying is only associated with a 0.049 increase in GPA. Exploiting the fact that being assigned a roommate with a video game system reduces time spent studying, they estimate that studying an extra hour a day improves GPAs by 0.356 grade points.

The first result is hard not to accept since roommates are randomly assigned. The last result relies on the usual instrumental variables assumptions. We should be concerned that being assigned a gamer roommate might affect GPAs for reasons other than less time spent studying and the authors do a number of checks to lessen this concern. Also, the sample is only is only about 200 which leads to imprecise estimates. That said, what a neat paper! Major bonus points to the authors for all their shoe-leather. They themselves began the Berea Panel Survey which included the time-diaries.

Paper links: NBER, non-gated version.

(h/t The Borjas Blog)

Seth Godin on PowerPoint

This post on PowerPoint is too good to quote. There are only a few blogs where I read every word of every new post. Seth Godin's Blog is probably the only one on the list that isn't written by a friend.

3 Most Influential Blogs

To me, personally, in no particular order:

The Becker-Posner Blog
When I first started reading The Becker-Posner Blog, I was amazed by their insights. After a while, I realized that they are simply applying neoclassical economic theory time after time. But they wield it powerfully. If one had no previous knowledge of economics, this may be the best place to start learning. The posts are well thought out and tackle big issues. Sometimes the positions they take are somewhat predictable but I always take this as a good signal about my own economic insight. Think about it this way--if you're writing a paper, for example, it's probably not a bad idea to wonder "what would Becker and Posner think about this?"

Art de Vany
This one has had the biggest impact on my day to day life. Most of the posts deal with how to eat and exercise in a way consistent with the conditions under which humans evolved. For about nine months before I started reading, I had diet hopped--I had lost 20 lbs but stagnated for the previous few months. Then I started following Art's suggestions when eating at home--lots more vegetables and fruits and no more starches. Another 10 lbs fell off pretty quickly. The great thing is that it's not like "being on a diet" at all so I don't have much of a desire to stop. That said, I haven't implemented the advice on exercise and I don't hesitate to indulge every now and then.

Marginal Revolution
While this blog is great for daily entertainment and economic insights, it's best for its "life hacks." My favorites include:

• The game to keep a museum exciting. In every room you visit you pick which piece you'd take if you were a burglar.
  
• Stop reading that book if you're not into it! (Perhaps this is common sense but for many, myself included, it's hard to do. I think people tend to view reading books as an accomplishment which makes not finishing books seem like failure. Or perhaps people like to be able to definitively say they didn't like something. Neither of these is a good argument for continuing to read something you're not excited about.)
  
• Don't try to eat healthy in restaurants. They specialize in unhealthy food. Make up for it by eating healthy at home.

EDIT: Gabriel weighs in with his three most influential blogs.

You know grad school has taken over your life when...

your initial instinct when you wake up at 4 in the morning is to check your computer to make sure your program is still running.

(Last night, my computer decided to restart itself due to a software update. A half a day lost!)

Everything Levitt Ever Wanted From His Children

My 4 year old has figured out how to read an opponent and take advantage of them.

Levitt on his 4 year old daughter "destroying" his other daughter in rock-paper-scissors. Seriously, though, I would be proud too.

Quick Thoughts on A Farewell To Alms

The most striking thing about the book to me is how much is done with a lot of a little. By that I mean that Prof. Clark has amassed a huge variety of bits of data to make his various cases. While it's frustrating that the little bits aren't bigger bits, it's hard to complain considering how far back in history we're looking at.

After arguing against a number of the conventional theories of the industrial evolution [edit: I swear I meant to write "revolution"], he argues modern growth came about because the characteristics that generate economic success were propagated throughout society by the relatively high fertility rates of the wealthy. The main piece of evidence for this hypothesis is from English wills which show that men with more surviving children tend to have more assets to bequeath. He admits that the rich are more likely to have wills but argues that this isn't a large concern since many men with modest occupations are found in the data too. But that's not quite the main concern. Kids are expensive, right? Then men with lots of kids are probably less likely to have assets to bequeath in a will. But this is probably a larger issue for poor men than rich men. So it seems like the poor men with lots of kids are most likely to be missing from the data. Put them back in and the positive relationship between wealth and children might shrink or disappear.

Levitt In Trouble Again?

Yesterday, he posted the following:

This is What Happens to People Who Listen to Too Much AC/DC...

They grow up to write economics papers like this one, which looks at whether participants in lab experiments get closer to efficient outcomes when exposed to one lead singer of the rock band AC/DC versus another.

I hope for this guy’s sake he has tenure.

Levitt didn't realize that the paper was a joke. The professor who wrote the paper emailed him with the real story. Here's Levitt's correction:

There Is Hope For Economics: The AC/DC Paper Was a Joke

I am delighted to report that the economics paper on AC/DC I blogged about yesterday was meant as a joke. It takes a lot of work to run an experiment on real people, just for a gag paper. It turns out they meant to play the same AC/DC song in both treatments, but made a mistake and accidentally played two different songs. Thus the genesis of the joke paper.

I still think this leaves Professor Oxoby with a bit of explaining to do as to why they were playing AC/DC as part of an experiment in the first place, however.

The comments on this second post, including one by Oxoby who posts the email he sent to Levitt, show that some aren't happy with the correction. Is Levitt in the wrong or are the people leaving comments too uptight?

A very short while back, Levitt blogged about "what [he] would do to maximize terror if [he] were a terrorist with limited resources": Part I, Part II, Part III. People didn't like that one very much either.

Bklog

Tournament Poker For Advanced Players by David Sklansky
I have not played very much and am not at all an advanced player. But I enjoy learning about the strategy. The biggest lesson I took from it: you need a better hand to call than you do to bet. I might have kind of known this before but Sklansky does a nice job explaining it.

Liar's Poker by Michael Lewis
This one is not about poker. It's about the crazy world of investment banking in the 1980s. Not as spectacular as Moneyball but that's to be expected since Moneyball was about sports, statistics, and valuation--I mean, it was practically written for me! Liar's Poker was still great, though. I found one passage particularly interesting in relation to Moneyball. Discussing the key to Michael Milken's success with junk bonds:

The ratings services [for bonds], like the commercial banks, relied almost exclusively on the past--corporate balance sheets and track records in--in rendering their opinions. The outcome of the analysis was determined by the procedure rather than by the analyst. This was a poor way to evaluate any enterprise, be it new and small, or old, large and shaky. A better method was to make subjective judgements about the character of management and the fate of their industry.

Milken sounds a lot like the foolish scouts who are described in Moneyball. They'd look at things like power, speed, and body type to value prospects while Billy Beane was able to beat the market by focusing exclusively on past performance and placing an immense value on on-base-percentage. So, what's the best way to beat the market?

Off the Books: The Underground Economy of the Urban Poor by Sudhir Venkatesh
Venkatesh is the sociologist who (along with Steven Levitt) wrote about crack dealers living with their parents. I started this book quite a while ago and it has been sitting on my "currently reading" pile of books for some time now a little less than half-read. Well, it's time for this book to go back on the shelf. Unfinished. The subject matter was actually pretty fascinating but the writing was really repetitive. I'd love to read a nicely edited second edition.

REJECTED

A few days after I sent the following letter to The Washington Post, the topics of published letters included how hot it is in Iraq compared to Washington, 1950s rock and roll, and how bad of a movie critic Stephen Hunter is. Ouch. Here's what I sent in:

-------------------------------------------------------------------------------

Dear Editor,

"High School Seniors Test Well in Economics" (8/9/07, Page D01) cites Bruce Damasio, who trains secondary teachers at Towson University, as writing "most students understood that if the going rate for babysitting increased, people would spend more time babysitting." A pretty basic concept in economics is that price (or wage) changes have both a "substitution effect" and an "income effect." If the wage for babysitting increases, it becomes relatively expensive to not babysit so people want to babysit more. This is the substitution effect that Damasio has in mind. At the same time, those who are already babysitting are all of a sudden made richer by their increased wage which makes them want to enjoy more leisure time and less babysitting. This is the income effect. The total effect on babysitting is actually ambiguous since we don't know which effect dominates. Much worse than Damasio missing this point is that such a flawed question may have made its way onto the national test past so many people who should know better.

-----------------------------------------------------------------------------------

I actually had my students read the newspaper article in class last week. Sure enough, they spotted the mistake.

Also, I should note that it's not clear that such a question did make it's way onto the test--Damasio might just have been using a (bad) illustrative example. It's also probable that the income effect is beyond the scope of high school economics which raises the obvious question "what's up with that?" And I mean that completely seriously--empirical estimates show that hours worked are not very sensitive to wage changes, suggesting that the income effect is indeed important.

Greg Mankiw, Craig Newmark, and Arnold Kling each have some things to point out about these test results.

Baseball discrimination estimates

Will comments on my previous post and does some math to argue that the level of discrimination estimated in this paper is too small to fuss about. (Of course, I'm sure he would agree that a small amount of discrimination is worth stomping out if the cost is small enough so let me focus on the magnitude.)

The paper finds that a pitcher is 0.34 percentage points more likely to get a strike if the umpire is the same race. Yes, this is a small number. Relative to the probability of getting a strike when the umpire is a different race, the gain is a bit over 1%. Still somewhat small but I don't think that's quite the right comparison.

It's important to keep in mind that more often than not, the strike/ball call is obvious. How many pitches in a game are really "close calls" that "could go either way?" My point is that the small estimate is expected since there so few times in a game when the umpire really has an opportunity to discriminate. He's discriminating a lot more on the margin than he is on average.

I'm sure you get the picture but here's an example. Think about a team that only uses pitchers that match the race of the umpire. How much more likely are they to get a strike on marginal pitches? Assume 150 pitches and 20 close calls. Further, assume that the umpire only discriminates on the close calls.

Increased probability of strike = 0.34 =
(# close-calls / total pitches) * (increased prob. of strike on close calls)
+
(# obvious calls / total pitches) * (increased prob. of strike on obvious calls)

Filling in the knowns,
0.34= (20/150)*(increased probability of strike on close calls) + (130/150)*(0)

Solving, we get that the increased probability of a strike on close calls is 2.55 percentage points. If you think there are less close calls per game (which I think there probably are), then the impact on the margin is greater.

EDIT: It's important to note that the 0.34 estimate is barely statistically significant at the 5% level and that they haven't clustered their standard errors. They should probably be clustering on the umpire. And if they did, my guess is that the estimate would probably no longer be statistically significant. So, despite the fact that I think this magnitude can be meaningful, I'm with Will in the skeptics camp as far as the overall effect is concerned. But the non-questec stadium (where umpires aren't monitored so closely) results are quite compelling.

Worse than a bridge to nowhere?

The D.C. school system received almost $4 million in federal funds for educating migrant children when it did not have any, city and federal officials said yesterday.

Here's the full article.

Competition for new mili-bots

Wired reports:

A government solicitation to robot-makers asks for a machine that can both "look into the window of a vehicle" and peek "under a vehicle undercarriage."

That July 17 solicitation kicked off a break-neck competition to award the bot-building contract. "The victor will be crowned Sept. 14 with a contract for 101 robots. The first must be delivered within 10 days," says Defense News.

Less than two months between the announcement and the competition? The military must really need these right now (which isn't surprising given recent events.)

A previous post on military recruitment and robots.

More discrimination in sports

This time in baseball. Very much looking forward to reading the whole paper. The Sports Economist tips us to the main results from the paper's FAQs.

1. What are the main results of the study?
There are three. First, umpires are more likely to call strikes for pitchers who share their race/ethnicity. The second result is an extension of the first: Umpires are more likely to express a preference for their own race/ethnicity only when their behavior is less closely scrutinized: 1) in parks where QuesTec (a computerized system set up to monitor and review an umpire’s ball and strike calls) is not installed, 2) in poorly attended games, and 3) on pitches where the umpire’s call cannot determine the outcome of the at-bat. Finally, game outcomes are influenced by the race/ethnicity match between starting pitchers and home-plate umpires. Home teams are more (less) likely to win a game when their starting pitcher and home plate umpire have the same (a different) race/ethnicity.

I don't doubt that there may be discrimination in MLB. At the same time, I worry about publication bias. I mean, with this study and the NBA study, it really leads you to believe that racism probably pervades all of sports officiating. That's two out of two, right? (Actually, neither are published in a journal yet but both have received considerable attention--you know what I mean.) I'm sure there are more studies on the way, for the NFL at the very least. Someone should do a comprehensive study of soccer leagues as well since so many countries have leagues--it would be interesting to see how the results differ across countries and continents. In any case, hopefully we'll hear about such papers regardless of the result.

Fellow Econ Grad Students

Are you working the right amount?

The basic lifetime labor supply theory says that you should work the most hours when your wages are the highest--this way you can kick back and enjoy leisure when your wages are low.

If you're still in grad school, you might consider that the return to working may be higher right now than any other time in your career since the quality of work that you amass during this time will determine your first job which has been shown to have profound effects on the rest of your career.

The Changing American Family

From Lundberg and Pollack's paper published in the latest Journal of Economic Perspectives.

• "The proportion of children under age 18 who are living with only one parent rose from 9 percent in 1960 to 28 percent in 2005."

• "25 percent of non-Hispanic white births, 48 percent of Hispanic births, and 70 percent of non-Hispanic black births were nonmarital in 2005."

I knew these numbers would be high but seeing them still took me aback. Also interesting

• "Total hours of housework in married couple households fell more than 20 percent between 1965 and 1995 (Bianchi, Milkie, Sayer, and Robinson, 2000) but, though husbands’ hours of housework increased substantially, wives still performed most of the housework at the end of this period. In the 2005 American Time Use Survey, married women reported an average of 16 hours per week of “household activities” compared to less than 11 hours for men."

Might men not wanting to do housework explain some of the decline in marriage? (Of course, the expected amount of housework is endogenous to the decision to get married so this is a difficult question to answer.)

The Benefits of Blogging

I pitched a paper idea to one of my advisors this morning and she was pretty enthusiastic about it. Yay for me! I take this as evidence that blogging can be productive since the idea was a direct result of reading blogs and writing this blog.

Now, back to "real work."

Beckham Debut: What Could Have Been

Early in the second half, the LA Galaxy were down 1-0 to DC United with Beckham warming up on the sidelines. The perfect scenario for him to come on and play hero, right? Well, his teammate, Kyle Martino, thought he'd raise the ante further and got himself thrown out of the game for a nasty slide tackle. Even Becks couldn't turn the tide with a one-man disadvantage.

The buzz when Beckham started warming up on the sideline was pretty amazing. It seemed like the whole stadium stopped watching the game to watch him jog laps. How do I know this if I wasn't at the game? Well, the TV producer apparently forgot there was a game going on as well as the Beckham bliss was only occasionally interrupted by the soccer game.

Clark vs. Colbert?

Lety tips us over at the Ambrosini Critique that Greg Clark, the increasingly famous economic historian here at UCDavis, is likely to be appearing on The Colbert Report to promote his highly praised new book Farewell To Alms. I'm pretty sure that her tip is due to inside knowledge. I would *love* to see Clark and Colbert spar. Poll: Who's more likely to say something controversial?

My first letter to the editor

Sent my first letter to a newspaper today. We'll see how the Washington Post responds. I had posted the letter here but I had to take it down since it has to be exclusive. If they don't take it, I'll post it here later. If they do take it, I'll let you know. I wonder how long I should give them (since they don't let you know if they're not going to take it)?

EDIT: I just realized that I put the wrong date for the article I cite in the text of my letter. Darn! At least I have a good excuse if they don't take it. Well, better than it being uninteresting anyways.

Grandma's generosity is a result of evolution?

I recently learned of "The Grandmother Hypothesis" (thanks Will). Basically, the hypothesis is that women evolved menopause because, beyond a certain age, it's more effective to invest in their existing children (and grandchildren) than it is for them to continue having children to ensure that their genes persist into future generations. The driving force is the fact that childbirth becomes more dangerous as women age. Neat story.

I believe economist Esther Duflo found behavioral evidence for this theory when she studied the South African Old Age Pension Program although I don't think she realized it (or perhaps she thought it not worth mentioning). She finds that payments to grandmothers improve their granddaughter's health (in terms of weight and height) but payments to grandfathers had no effect. (Interestingly enough, neither has an effect on grandson's health.) Duflo argues "grandmothers are likely to have a stronger incentive than grandfathers to invest in children because they will benefit from them for a longer time" since they are expected to live longer. This is a reasonable explanation but the grandmother hypothesis seems a nice alternative.

Politicians are such easy targets

but it's their own fault. (Or is it ours?) Bryan Caplan with a good find:

Another debate gem: Hillary on energy policy.

CLINTON: ...But this issue of energy and global warming has the promise of creating millions of new jobs in America... So it can be a win-win, if we do it right.

It's hard to interpret this charitably. Hillary really seems to believe that the diverting of millions of people to a new task is a free lunch. Has she never read Bastiat?

Sorry, stupid question.

Dealing with the soldier shortage...

Three SWORDS, the world's first weaponized robot, have been deployed to Iraq. The Army has ordered 80 more of these remote controlled machines. Wow. (To think that I was impressed by the video camera mounted pistol in The Bourne Ultimatum!) See the the Wired article for humorous (?) quotes about development bugs and an amazing video.

Chicago Tribune reports (free registration required) on the army's "quick ship bonus," a $20,000 bonus for new recruits if they are willing to begin basic training within a month of enlisting. I think the promise of a SWORD would be much more effective. I wonder how much they cost?

Don't feed the Stata

Today, I set out to test how the amount memory allocated to Stata affects efficiency. The "set mem ___" command sets the amount of RAM to allocate to Stata. I remember reading something at some point that mentioned allocating too much memory can slow the program down but I figured it would be better to see for myself. Sure enough, it did.

The experiment was much like the previous ones. I did five trials of a program with 900m versus 450m allocated. I ran programs with 900m, then 450m, 450m, 900m, 900m, 450m, and so on so that one allocation wasn't always running before the other. I ran programs of varying lengths for each trial. Here are the results:

Trial #. 900m time, 450m time
1. 7:26, 6:22
2. 2:12, 2:02
3. 1:56, 1:40
4. 5:33, 4:43
5. 6:52, 6:16

About a 12% reduction in times by cutting the memory allocation in half. Don't feed Stata too much memory or it will get bloated and slow down.

The problem with free blogs

I really like the (EDIT: now former) title of my blog ("Marginal Revelations") because of what it conveys. But it is a ripoff of Marginal Revolution which I have a great deal of respect for. I came up with about 15 or so alternative names this evening. Of course, they were all taken already. And nearly every one of them had only one or two posts! This is not surprising since they're free.

This wouldn't be a problem in the standard theoretical market. These people clearly do not value their blog names very highly so I should be able to buy them from them for cheap and we both would benefit. But this doesn't happen because there is a transaction cost which mainly consists of me figuring out how the heck I would go about doing that.

Sure enough, there are blog services out there that I could pay for (like typepad) and I'm sure I'd be able to find a name I liked. But they're too expensive so I really shouldn't complain. But I'd recommend to Blogger that they institute some sort of inactivity clause that takes blogs away from people who haven't used them after a year or so.

I think I might just change it to something dry but informative like jmlindo.blogspot.com (because "jlindo" and "jasonlindo" are already taken, of course.)

EDIT: And it's official. I've moved to jmlindo.blogspot.com. Obviously, you've figured this out if you're reading this.

Books, books, books

I recently finished John Scalzi's The Ghost Brigades, a sequel to Old Man's War. The major sci-fi element of the series is the technology to transfer consciousness from body to super-enhanced military body, the most important feature of which is a computer enhancement to the brain humorously called a "BrainPal." The coolest tech-fantasy idea in the book is the integration of minds via the BrainPal. I mean, can you imagine having access to another persons mind or giving someone else access to yours? And then imagine this on a greater scale. Ridiculous! And so cool! The story's neat as well. I don't know what it is about sci-fi and war drama that go so well together but they do. Scalzi peppers the story with nice touches of angst, comedy, romance, and references to other popular sci-fi books and movies. Definitely recommended for a fun and pretty easy read.

Is it safe to comment on Harry Potter and The Deathly Hallows yet? Well, I don't have too much to say anyways and no spoilers of course. It was largely what I expected. Quite enjoyable. The section with Harry walking into the woods was spectacular. At the same time, modern times have seen much better fantasy fiction from Britain in the His Dark Materials Trilogy. Hopefully the upcoming movie starring Nicole Kidman will raise interest.

I also picked up the first volume of The Astonishing X-Men written by Joss Whedon (of Buffy and Firefly fame). It was good but I expected more based on the great reviews. Maybe it's supposed to get better in future volumes.

War and Child Maltreatment

The stress of having an Army spouse in a combat zone leads to a 60% increase in the rate of moderate to severe maltreatment of children by the spouse left behind, researchers said Tuesday.

This is from an LA Times article describing a recent study in the Journal of the American Medical Association. I think too much attention is being placed on the spouses. The stress of having a parent in a combat zone is surely incredible as well. The stress the kids are under may affect their behavior in ways that make them more likely to be maltreated by their remaining parent. The original study seems to miss this point as well.

To be clear, I'm not "blaming the victim" but determining good policies to improve these sorts of things relies on understanding what leads to what.