Showing posts with label Heterogeneity. Show all posts
Showing posts with label Heterogeneity. Show all posts

Tuesday, December 29, 2015

Labor Income of Natives and Immigrants

Below, Corrections displays the labor income of natives (those born in the United States and its territories) and nonnatives (those born in other countries) over time (click to enlarge).  Unfortunately, the CPS only started asking a question about nativity whose answers can easily be compared in 1993.
Interestingly, the gap has fairly steadily closed in percentage terms, as depicted below (click to enlarge).
While historically, it's not too uncommon for immigrants to make more than native workers (there are strong selection patterns in immigration (there's a reason some people come to the U.S.), and immigrant workers have far less access to welfare programs than natives and lower take-up of the programs they do have access to, meaning they must rely on labor income more).  

Monday, September 2, 2013

Probability a Person Lives with Parents by Age

Below, Corrections takes the cross-sectional data on 2012 from the Current Population Survey and calculates the probability that one is the child of the head of household, by age from 16 to 85 (click to enlarge).  The probability a child is head of household with a parent present is small (single-digit percentages), even as they grow older (not shown).
Additionally, we display the time series evidence for four ages:  23, 25, 27 and 29 years of age (click to enlarge).

Tuesday, December 25, 2012

Women's Labor Force Decisions by Marital Status over Time

Below, Corrections depicts the proportion of women by marital status and labor force status over time from the Current Population Survey (click to enlarge).
What could cause this?  Why are married women working so much more?  It can't be anything special about being married--nonmarried and married women show the same pattern.  Women in general are working more.  

Even though we know it isn't anything to do with martial status, we then depict the proportion of married women by labor force status over time (click to enlarge).  Women used to work about 35% of time (other sources give 35% extending back further) to around 60% of the time, an increase of 35% (doubling the proportion of women working).  
Corrections then offers the proportion of women by martial status, educational status, and labor force status over time.  One trend dominates the pattern: women are becoming more educated, so both red lines decline while both blue increase (click to enlarge).
This is depicted more clearly below (click to enlarge):
Instead, we can normalize by the population of all women within an educational category (click to enlarge):
And we can normalize that to the proportion that was working in 1965, to see how much these proportions change over time (click to enlarge):





Households by Number of Earners

Below, Corrections depicts Households by number of earners from 1980-2011 (click to enlarge):
Making the same graph with proportions (click to enlarge):


Saturday, September 24, 2011

AAA vs. BAA Bond Spreads

Below, Corrections takes the difference between daily AAA and BAA rated bonds (Moody's, from the FRED database) and displays recessions (click to enlarge).
When the data from Operation Twist and the subsequent days become available, we'll put those graphs up too.

Saturday, March 19, 2011

Give Peaceful Resistance a Chance

New York Times opinion "Give Peaceful Resistance a Chance" (March 9th, 2011) offers insight into part of an economist's raison d'ĂȘtre. The article by Erica Chenoweth, a Professor of Government at Wesleyan University, misunderstands heterogeneity in revolutionary starting conditions. Her claim:
Unfortunately for the Libyan rebels, research shows that nonviolent resistance is much more likely to produce results, while violent resistance runs a greater risk of backfiring.
To back up this statement, she claims that:
Indeed, a study I recently conducted with Maria J. Stephan, now a strategic planner at the State Department, compared the outcomes of hundreds of violent insurgencies with those of major nonviolent resistance campaigns from 1900 to 2006; we found that over 50 percent of the nonviolent movements succeeded, compared with about 25 percent of the violent insurgencies.
Why is this bad research? Because not all revolutions have the same starting conditions. Imagine a world in which there exist dissidents who optimally choose between armed rebellion and peaceful protesting. These dissidents know the government they face and the probability of success of a given venture. Then the observed probability of failure for armed revolution may be higher than of peaceful protest even when both were always chosen optimally. To understand why Chenoweth and Stephan get the results they do, observe the following conjecture in figure form (click to enlarge).


A rational rebel will take the upper envelope of these two decisions. If this is the case, then we will see violent revolutions under oppressive regimes that generally fail, and peaceful protest under non-oppressive regimes that generally succeed. There will be no Ghandi's under Hitlers, Stalins, and Mussolini's. Ghandis can only be successful under men who are inherently peaceful when others are peaceful with them, such as Churchill. Similarly, it may often be difficult for Malcolm X's or The Weathermen to succeed in vastly less oppressive societies, where hoses and dogs rather than machine guns and concentration camps are used to control protest. They are unable to gain the sympathies of the populace. Martin Luther Kings are better suited for the United States than the Malcolm Xs or Bill Ayers of the world.

It is no coincidence that Bill Ayers changed from attempting to bring down the United States by armed rebellion to bringing it down from within--he reoptimized.

The conclusions Chenoweth attempts to draw are faulty due to sample selection.  Armed rebellion may be more likely to succeed conditional on the situation but less likely to succeed when looking at the unconditional success rate.

Sunday, October 10, 2010

The most conservative court? Hardly

Boston Globe article "The most conservative court? Hardly" (October 10th, 2010) discusses the leanings of the Supreme Court over the last few years. What it lacks is the recognition that the average justice's opinion is not what makes up a court--it is the median Justice's opinion. Corrections offers a simulation of the median and mean of a court composed of 9 justices (though the number has changed, the spirit of the simulation remains). It is important to note that all that follows below is a simulation.

Presidents are elected every 4 years with a 50/50 split in expectation between parties. Each President picks up his party's preferences with a small deviation of his personal preference. If a Justice leaves, one is appointed with the current President's ideology plus a noise term. If a Justice does not leave, he changes his opinions slightly from last period in a random walk. Each Justice has a 5% chance of leaving in any given year.

Then for 9 seats from a simulated ~235 years, we can plot the ideology of the person sitting in that seat, depicted separately for each seat graphically below (click to enlarge).



Similarly, we can merge all the Justices into one graph, if it helps understand the magnitude of individual shifts (click to enlarge):



But what is important for the court is the median Justice, not the mean, and not any individual. We present the President's ideology along with the mean and median Justice ideology below (click to enlarge):



In the simple simulation above, for most reasonable parameter values, the median Justice, in part because the parties differ much more than the personality noise for Presidents and the ideology noise for their Justices. Indeed, in any number of most simulations we ran, the median variance was much greater than that of the mean. This is an important distinction that the Globe's discussion of individual Justices did not encompass (though its discussion of decisions remains relevant).

Saturday, October 2, 2010

The New American Normal

New York Times article "The New American Normal" (September 27th, 2010) states that there may be heterogeneity in the ability of traders to make money during various market conditions. Corrections doesn't see this as being the case. We expect that a trader has an equal opportunity to have a positive expected value on a trade whether the market is highly volatile or not.
Fragmentation holds sway. The stock market used to be a fair proxy for the state of the economy. Now it’s a market of traders, not investors. They want to know what the spread is today and tomorrow; they can make money on the way up or down; they care far less about U.S.A. Inc.

So the market goes where it goes — up of late but largely directionless (which makes it harder on those up-or-down traders) — while out on Main Street the struggle to make family payroll continues. People work longer hours, they juggle how to cover their kids’ needs, how to de-leverage just a little — and they’re still meant to “consume” for the economy’s sake.

First, for the ill-defined class of "up and down traders", we might consider they do better when the market is highly variable. However, a quick view of the 30-day average S&P 500 price variance dispels this notion rather quickly (click to enlarge). If anything, Corrections expects that the average trader did better in the low volatility areas than the high (NBER recession dates are colored in grey).

Either way, it's ludicrous to claim that traders like one market environment over another, unconditional on their current assets. Unconditional on current assets, a trader who believes the market will be constant will be able to make money off selling a put below the current price (believing a stock won't go below the sum of strike price and premium) and selling a call above the current price (believing a stock won't go above the sum of the strike price and premium). A trader can flip sides on the trade if he thinks volatility will be high. If the market is undergoing a constant increase, then demeaning by the expected trend yields the same trading strategy. Whatever the market conditions, it's rather simple to construct trading strategies that require simple adjustments. The level, rate of change, and volatility won't matter.

The only manner in which changing market conditions may matter to a trader is an increase in the cost of capital (for deals requiring leverage) a decrease in their ability to utilize specific knowledge or expertise (analysis of mergers and acquisitions may presumably require expertise and contain a cyclical trend), or if the trader already owns positions in the market and does not want those to decline--distinctly separate (though difficult to distinguish without data on specific trends) from their ability to make money off present market conditions.

The Campaign Disconnect

New York Times editorial "The Campaign Disconnect" (October 1st, 2010) defines and interprets wealth and income dispersion in the United States. Corrections has a different take:
In an era of extreme economic inequality (which is another way of saying economic unfairness) [...]
We forgo analysis of the ludicrous definition of "fair" Bob Herbert uses. What the Times does not note is that high dispersion in wealth and income might be better termed "opportunity" and "motivation." Take the extreme example: complete equality in wealth. There is no opportunity for wealth to increase, and therefore no motivation to work or be creative.

In this respect, while it seems a concern for wealth and income dispersion "equality" is ubiquitous, it appears to miss inequality as a motivating factor in human creativity.

Thursday, September 23, 2010

Value of College Degree Is Growing, Study Says

New York Times article "Value of College Degree Is Growing, Study Says" (September 21st, 2010) gets the correlation/causation distinction correct. However, it doesn't give the clear causal reasons why better educated and wealthier people eat more healthily and exercise more: while people often face the same price of an activity, they often face different shadow prices, the relevant price for making decisions.
The report, first issued in 2004 and updated in 2007, also described social benefits: those with a bachelor’s degree, it said, are more likely to volunteer, vote, exercise and have health insurance and pensions. They are also less likely to smoke, be obese or have low-birth-weight babies. It did not assert that a college education, by itself, was responsible for all those differences.

'Correlation is not the same as causation,' Ms. Baum said. 'But that said, the people who have done careful statistical analyses, controlling for demographic characteristics like income and family background, have overwhelmingly concluded that there’s some causation here, that some things that happen to you in college, for example, would make you more likely to adopt healthier behavior.'

Better educated and wealthier people have more incentive to live longer because their time is worth more. Take Kevin Murphy's shadow price of a cheeseburger example (briefly mentioned at the end of this interview). Eating unhealthy cheeseburgers shortens your life, but you gain happiness from them. The time of a low-wage person should be valued by that low-wage person as their wage (or outside wage, if the two are only approximately equal). While state-dependent utility disclaimers apply, the thrust of our argument will be robust to secondary and tertiary corrections.

Let us imagine that the time a rich person is willing to give up for an extra hour of his life is $200, but a poor person is only willing to give up $100. Then if a cheeseburger takes an hour off of an individual's life (for instance), then the true cost to a rich person is $204, while the cost to a poor person is $104. The shadow prices the two individuals face are different. Unhealthy decisions cost rich people more because they value their lives more.

When people decide to become educated, they induce themselves to have different marginal utilities and therefore make different decisions due to facing different shadow prices--a cheeseburger is more expensive for a rich person.

Wednesday, September 22, 2010

Bridging the achievement gap

Los Angeles Times opinion editorial "Bridging the achievement gap" (September 22nd, 2010) discusses the achievement gap between black males and all other students (black females and white males being the primary groups of comparison). It speaks only of educational means to fix the graduation gap, while discussing crime. Corrections would like to entertain a different possibility that might help solve both. The Times also confuses correlation and causation.
These disparities aren't new — the Schott report could have been published a generation ago. What is new and noteworthy is solid evidence that this gap can be bridged, with well-tested approaches that don't require massive changes in public education and don't depend on superhero teachers and administrators.
An economic idea might be that individuals, both black and white, make decisions about education today based on what they believe their income differentials will be tomorrow. One way to encourage education is to ensure higher wages for the educated. Another is to ensure lower wages for the uneducated.

The Times suggests that some of these students might be on the "prison track." "All too often they're on what educators privately dub 'the prison track.'"

If the Times is concerned that black males (or, for that matter, individuals of any race or gender) are opting out of educations and into lives of crime, one way of reducing their involvement in crime and increasing their graduation rates might be to lower their future wages as criminals.

We do a quick back-of-the-envelope calculation to test this hypothesis. We should see a correlation between an increase in law enforcement officers tomorrow and an increase in graduation rates. For the 50 states from 1998-2003, we plot the two, and offer a fitted least squares line. This is displayed graphically below (click to enlarge).
The relationship is indeed positive, which is itself phenomenal. If high schoolers were myopic and unresponsive to future police presence, we would have expected a drop in graduation rates to result in an increase in police next period--an increase in bad high school students should make more police next period a necessity. The fact that we see this indicates that the difference between our two effects is rather large. At a first glance, while the relationship is only near significant, it would appear tantalizing. For those concerned about the outliers, the relationship remains positive dropping them from a fixed effects panel data regression.

The Times discusses young black males, their graduation rates, and crime. Following our above analysis, we might think that a way to increase the graduation rates of young black males (who head into crime at higher rates than young white men or young black women) might be to decrease their wage differential between crime and legitimate employment through the hiring of more law enforcement officials over the course of several years. This would have the added effect of decreasing crime. Indeed, if individuals are forward looking and we have a believable commitment mechanism, we needn't wait to see the effects.

Clearly the analysis Corrections provides is both preliminary and inconclusive--it is merely suggestive. Nevertheless, it offers an interesting avenue to improve education by rational forward-looking individuals of all races and genders.

Beyond this discussion of heterogeneous impacts by race of an increase in future police presence on future crime and graduation rates, we might also add a particularly offensive quote by the Times:
A large-scale study in Chicago found that 74% of the boys who attended preschool graduated from high school, compared with 57% of those who didn't.
This is a correlation. It is not clearly causal.

Sunday, August 29, 2010

What if the end isn't near?

USA Today article "What if the end isn't near?" (August 23rd, 2010) discusses a large subpopulation in America that ostensibly believes that the Second Coming of Christ will occur within the next forty years. The article is deeply concerned about this and its effects on public policy (e.g. if Nuclear Disarmament or Global Warming are long-term threats, we need spend resources on them, as the world ends before they become problems).
A new poll from the Pew Research Center for the People and the Press finds that roughly four in 10 Americans believe the Second Coming will happen by 2050.
and
Thankfully, Wigg-Stevenson and many new-breed evangelicals like him are refusing the kind of end-times bait that lets believers off the hook — off the hook of inspired social action that can make their faith a powerful blessing to their society and their time.
Corrections, from its own a priori beliefs, finds this statistic difficult to believe. The proper economic method for discerning beliefs is to watch what individuals do, not what they say. Our a priori beliefs are so strong that Corrections suggests that individual economic activity simply doesn't match up with these beliefs--people are professing things to pollsters that they don't believe.Corrections ventures out of its area of expertise into christian eschatology to understand this poll figure. Any corrections are welcome; the purpose here is just to get a grasp on what individuals might believe, as various interpretations impact economic behavior.There are five important events or periods that are relevant to the Christian End Times: 1) The First Coming, 2) Tribulation 3) The Second Coming 4) The Millenial Reign 5) The Last Judgement.
  1. The First Coming kicks off the sequence of events, bounding the sequence of events and marking the beginning of the "countdown".
  2. The Tribulation is a period of time after the Rapture (taking of Christians to Heaven, and their disappearance on Earth). In this period of time, for many, the Four Horsemen of the Apocalypse come, many individuals die.
  3. The Second Coming is the arrival of Christ on earth.
  4. The Millennial Reign is the Thousand-Year Reign of Christ before Judgement Day.
  5. Judgement Day is the point at which all economic activity ceases (e.g. August 29, 1997 as Judgement Day would signal the cessation of all economic activity, as individuals are separated into good and bad, and sent to the afterlife).
First, we stipulate all individuals believing in the Second Coming are Christians. In our understanding, there are several ways to interpret "The Millennium," mentioned in the bible before the Last Judgement (after which we suppose all economic activity to cease). These beliefs can be broken down into two categories and two sub-categories within those.The first is Premillennialism, which includes both Post-tribulational Premillennialism and Pre-tribulational Premillenialism. These believers hold that there is economic activity after the Second Coming--that the Second Coming occurs before the Millennial Reign.

In this case, these individuals do not believe that economic activity will cease upon the second coming. (Though Pre-tribulational Premillennialists may believe that the rapture will remove them or others from economic activity upon the Second Coming. Neither of these allows for the end of the world before 2040, requiring at least a Millennial Reign.

The second category are individuals who believe the Second Coming and the Last Judgement will be concurrent--in this case, all economic activity ceases. Included in this are Postmillennialists and Amillennialists, the former thinking that the Millennial Reign will occur before the Second Coming (and may have been happening for some time) and Amillennialists believing that the Bible only refers to a "symbolic" Millennial Regin. Both allow for the end of the world to occur in or before 2040.In any case, the article can only be concerning itself, as far as Corrections can see, with Postmillennialists and Amillennialists, as it would be difficult for either Premillenialists to believe the Second Coming will happen, due to the requirement of the Millennial Reign which has not happened--these people should still be willing to invest in their futures or their children's futures, as the Second Coming may happen in 2040, the world doesn't end.

Do people act as if the world will end by 2040 rather than at an indeterminate time? Corrections suggests not. To understand why, we merely need to understand that individuals would have starkly different consumption patterns. To understand why, take two individuals, starting out with the same consumable resource. They enjoy consuming it, but given they don't consume it, it grows or reproduces at some rate. An example of this might be any animal herding, or saving money (which grows at the real interest rate). Individuals are impatient, but also want to smooth consumption. One individual believes in an infinite-horizon world, where they save for themselves and future generations. Another believes the world will end in forty periods. How would their consumption patterns look? We solve the dynamic programming problem for when to sell a herd stock for both individuals. Their stock of animals and number of animals sold is displayed graphically below (click to enlarge):


As one can see, savings and consumption patters are starkly different in the two groups quite quickly--people who have dynastic preferences and solve an infinite-horizon problem (or something approximating it) are able to take advantage of exponential growth in a way that finite-horizoned individuals cannot. The question is whether or not we see this sort of behavior among the 40% of the population the Pew Research Center claims. It is also worth noting that the difference seen would be enlarged further by any comparison before today's date (we assume the same resources today--were individuals to have started with the same resources five years ago, a difference would be even more noticeable, because there is more time for divergence).

How might we see this in public policy? Any individual believing that Judgement Day would happen before 2050 and born after 1983 will not see any social security benefits, while paying in for social security and other retirement programs. Indeed, individuals born before 1983 will not come remotely close to being paid their contributions, and should rebel equally agianst this program.

Such individuals should not be saving for retirement, and certainly not be taking care of their bodies--many of this 40% who believe the world will end by 2050 should begin smoking, and planning for a family may be seen as mildly short-sighted.

In summary, Corrections believes that the lack of evidence on this 40% of the population, the lack of articles noting the incredible rise of unhealthy behavior and savings is evidence of individuals not believing what they claim to believe in surveys. Corrections might further note that while one may joke about short-sightedness among Americans today, the question is about whether or not people are behaving with the degree of extremity necessary to act as if the world was going to end in 40 years.

Friday, August 27, 2010

One number can't illustrate teacher effectiveness

Los Angeles Times article "One number can't illustrate teacher effectiveness" (August 25th, 2010) criticizes Richard Buddin's scoring of Los Angeles teachers, arguing that it isn't taking everything into account and that there's an "ethical issue" publishing his research:

Given analytic weaknesses, the ethical question that arises is whether The Times is on sufficiently firm empirical ground to publish a single number, purporting to gauge the sum total of a teacher's effect on children.

Corrections had a number of issues with the article's criticism of Buddin's procedure. However, the more interesting issue was the author's raising of "ethicality" in the Times decision to publish Buddin's research. Theory suggests that unions may raise short-run pay but they flatten skill differentials. Perhaps to that end, teacher's unions have nearly uniformly opposed the ranking of teachers and anything that might help that process.

One reason for this is so fellow travelers might then criticize any empirical ranking that breaks a union's power by encouraging best practices and getting rid of bad teachers. What, then, might a strategy be to break this cartel of unions denying statistics, and education professors criticizing studies using bad statistics? To publish the best studies we can using the statistics we are given. Why?

Let us imagine that there are two types of teachers, good teachers, and bad teachers. They both have the same baseline utility. Both their utilities may be decreased by increased supervision. However, given that they'll be ranked, good teachers would rather have good statistics. The idea is displayed graphically below (click to enlarge).


What might this do? If they aren't being graded, both good teachers and bad teachers prefer to obstruct good statistics being collected. However, if they are being graded, good teachers now prefer good statistics while bad teachers like them even less. However, a wedge has now been created, and it's an empirical question whether or not good teachers will be able to outvote bad teachers in the quest for the collection better statistics.

In this vein, publishing well-done, competent research that admits its flaws (which an article criticizing it then rehashes) and encourages the destruction of union power to the detriment of bad teachers and benefit of students would appear the only "moral" choice.

Saturday, May 29, 2010

America's 'casualty gap'

Los Angeles Times opinion editorial "America's 'casualty gap'" (May 28th, 2010) reports the difference between the percentage of total wartime casualties suffered by members of poor communities relative to members of rich communities.
Nationally, in the Korean, Vietnam and Iraq wars, communities in the lowest three income deciles suffered 35%, 36% and 38% of the casualties, respectively. Yet communities in the top three income deciles sustained significantly fewer casualties — 25%, 26% and 23% of the casualties, respectively.
The United States has a volunteer army. Soldiers are compensated by regular pay, hazard pay, enlistment bonuses, government benefits, and well-earned gratitude from present and future generations. When the United States has a volunteer army, which it has since December 1972, the last month in which an individual was conscripted into the U.S. Armed Forces, it is an exercise in futility to argue any sort of discrimination. Individuals freely choose the Armed Services over their other options. They further choose their branch of service, as well as their military occupational specialty, generally speaking. If poorer people choose the military, it would appear, in a rough analysis, that they are benefitting more from its presence.

This may be especially true during wartime. Corrections cobbled together military pay for E-2 (an enlisted pay-grade corresponding to a Private in the Army, PFC in the Marine Corps, Airman in the Air Force, and Seaman Apprentice in the Navy and Coast Guard. It is a pay grade relatively rapidly achieved for enlisted men. Military pay sheets for every year were not easily available. Corrections imputed pay for those years in which it is not, denoted by a circle. Years featuring a war in which more than one-hundred Americans died (as well as the first three years of Operation Enduring Freedom, in which fewer than 100 Americans died) are denoted in red, while years without such a conflict are denoted in blue. It appears to Corrections, generally speaking, that post-draft wartime has caused more rapid increases in inflation-adjusted military pay. Therefore, it is difficult to discern without more careful calculus whether or not individuals are being compensated for the risks they are taking--with heterogeneous valuations, we might expect wartime military service to be better for poorer Americans who choose to serve, rather than worse. Our data is displayed graphically below (click to enlarge).



We note the sharp spike in pay occurred when Richard Nixon was engaged with the idea of an all-volunteer army.

Corrections should further add that including Operation Enduring Freedom, Operation Iraqi Freedom and Operation New Dawn in their analysis, without including the enrollment, average length of service, and rate of ascent figures for each income decile is egregiously misleading. In fact, both the lower class and the upper class are underrepresented in enrollment--this article's analysis would suggest that the middle class suffers disproportionately the costs of war.

In addition, a low-income recruit may not be identical to a high-income recruit, making it difficult to compare their wartime outcomes directly. For example, it is well known that income is correlated with education. If the army recruits more "high-quality" soldiers from higher income brackets, then we would expect these "high-quality" recruits to more quickly achieve higher and higher military rank, making them potentially less likely to be in the line of fire than their low quality counterparts. In this sense the article may be taking issue with the fact that more intelligent soldiers are less likely to die in battle. Similarly, if the poor serve longer than the rich, these statistics could be driven by the relative density of poor servicemen. Ultimately, the number of confounds in this analysis make it completely incredible.

Saturday, May 22, 2010

Can an Enemy Be a Child's Friend?

New York Times article "Can an Enemy Be a Child's Friend?" (May 17th, 2010) states that teenagers who face their classmate's enmity and reciprocate it are better socially adjusted. Throughout, the article's context suggests that such behavior could cause individuals to become better adjusted. Corrections sees heterogeneity rather than causality.

In a series of recent experiments, a group of psychologists at the University of California, Los Angeles, recorded mutual dislike among 2,003 middle school students. Unlike previous studies on the same topic, these researchers also compared children who reciprocated a fellow classmate’s dislike with those who did not. Students who were not named at all on anyone’s blacklist were excluded from this analysis.

This comparison found that the girls who returned classmates’ hostility scored significantly higher on peers’ and teachers’ ratings of social competence. They were more popular and widely admired. The boys who did the same scored highly on teachers’ ratings of classroom behavior.


Corrections is perpetually pointing out the difference between correlation and causation. In a parallel argument, we note that these correlations are scarcely even suggestive of causation when we are dealing with optimizing agents. Imagine that an individual faces enmity from a classmate. Their ability to respond successfully by reflecting enmity back is heterogeneous in the population--they vary in their effectiveness. Furthermore, socially competent people have a greater degree of efficacy in their ability to reflect enmity. Were we running the analysis the Times runs, we would display the following relationship (click to enlarge), which clearly displays a positive relationship between an individual's enmity reflection decision and their social competence:



However, let us imagine that social competence and effectiveness at reflecting enmity have the positive relationship that we graphically display below (click to enlarge):



Then we might say that all individuals who are effective at reflecting enmity do so, and all those that do not, don't. We have in truth the relationship (click to enlarge):



Ordinarily, when we point out that correlation is not causation, we note that a third factor is likely causing both. Here, we posit causality: enmity doesn't cause social competence--social competence causes enmity.  Further, in this causal relationship, boosting enmity among those not displaying it would clearly hurt them (we display this in the last diagram). Students who don't display enmity don't do so for a reason.

Tuesday, February 9, 2010

When athletes praise God at the Super Bowl and other sports

Christian Science Monitor opinion "When athletes praise God at the Super Bowl and other sports" (February 9th, 2010) ignores possible utilitarian concerns in its invective against Drew Brees praise of god on national television.

'God is great.'

So said Drew Brees, the most valuable player in last Sunday’s Super Bowl, after leading the New Orleans Saints to an upset victory over the Indianapolis Colts.

Such comments have become commonplace on American television, where athletes routinely thank God in postgame prayers and interviews.

Is this a problem? I think it is. And to see why, try to imagine if Brees had made a slightly different statement: 'Allah is great.'

It is worth noting that approximately 76% of the United States are Christians. Corrections imagines that among Super Bowl watchers, and American sports fans, it's likely higher (and more intense).

In a purely felicific calculus, average gain that individuals who watch may get from hearing a praise of their chosen deity multiplied by their number is likely greater than the average loss from individuals who watch and don't like hearing praise of god. The author's comparison would make the transition from somewhere between a 3-to-1 and 9-to-1 christian-to-other watcher, to a very small minority-to-a large majority, if an Islamic prayer were said.

The author's comparison is false, if we examined it on Benthamian felicific calculus, or any reasonable weighting to achieve a comparison between aggregate benefit and aggregate cost.

Sunday, January 31, 2010

Student1776 on "Don't Legalize Marijuana," and Response

Corrections appreciates acuminous commentary. A comment by “Student1776” was left in response to our post “Don’t Legalize Marijuana”. It was thoughtful enough to warrant its own post in response. Corrections is willing to repeat this activity for insightful commentary.

The post by Student1776 follows:

The writer of the blog makes an excellent point that the use of taxation as a means to control the extent of use. There are at least two additional pertinent elements. First, illegal status tends to constrain use differentially to areas where law is less respected or at least less effective. In the US the illegal status of marijuana or crack cocaine or other drugs tends to confine sales, distribution and to some degree consumption to ghetto areas. Making marijuana or crack cocaine legal would allow the expansion of sales and distribution to all areas - for example the suburbs - likely resulting in expanded use and an expansion of adverse social consequences both in terms of numbers of users and in terms of affecting more empowered parts of the electorate whose political pressure would doubtless be made manifest. Second, as one considers the wider principle of legalization and taxation there is a different aspect to consider. Drugs affect individuals differentially for a variety of biological and other reasons. For any given drug different people have different propensities to addiction. For example, about 6-10% of people exposed to alcohol for as little as a first exposure to several exposures will over time become addicts while 90+% of people who consume alcohol can take it or leave it. These latter people with a propensity not to be addicted are said to be able to "chip" alcohol. For opioids and tobacco the same phenomenon occurs but the number of potential addicts is larger - in a broad ballpark around 20% of people being at risk for addiction with 80% of people for example being able to use an opioid for pain for an extended period without coming to exhibit drug seeking behavior (that is to "chip" opioids or cigarettes. For amphetamine type drugs the proportion of addicts to chippers is far higher - likely on the order of 30-60% depending on the amphetamine with the number of chippers being correspondingly lower (70-40%). The point is that while marijuana has a relatively low rate of severe addictive behaviors associated with it and a high rate of chipping, other drugs are less benign. People who are addicted do continue to show some level of "rational" behavior in the sense of price responsiveness but addicts are by the nature of the disease incompletely rational. Addicts will engage in extreme and irrational activity including violence and law breaking at felony levels. The issue is that while drugs are illegal and distribution is highly restricted there are many people who are potential addicts who are simply not exposed to the addictive drug and as a consequence are able to live productive lives and not be addicted. Pricing issues might to some degree permit a similar constriction of the potential exposure of addicts but for many potential addicts not exposed at this time because of limits of distribution, their financial characteristics may allow them to surmount limitations on exposure due to pricing. It is also noted that if taxation is raised to too high a level then the taxation itself will be surmounted and we will have just created a new kind of illegality. (Not unlike the current cigarette smuggling industry). The bottom line is that the Corrections blogger is correct that taxation could be used to help control exposure, one can anticipate far wider distribution and for the highly addictive substances far higher levels of addiction and associated social damage in localities and social circles currently out of the loop of distribution.


Four points have been made that it is incumbent upon Corrections to dispute, in one form or another.

1) Illegality has differential effects on area that taxation does not have. Specifically, Student1776’s conjecture is that currently use is kept in relatively indigent areas—post legalization, it could spread to wealthier areas. This, in turn, may lead to more users, and empower “undesirable” political classes.

Concerning the first point, Corrections agrees and considered this point. However, it is important to note that there is a reason that use was constricted to indigent areas to begin with. Specifically, that these areas had low opportunity cost of both use and penalty. But it is worth noting that when the government makes something illegal, the black market has no means of writing enforceable formal contracts.

This means that in order to enforce contracts, firms use force. Firms that dominate the industry tend to be those best at wielding violence, rather than those with the most efficient methods. This, in turn, creates an industry that has a lower cost to producing violence on competing firms, consumers, and government.

Corrections posits that this helps propagate the very indigent communities that the author concerns himself with. Were these industries replaced with companies like Johnson & Johnson, Pfizer, and GlaxoSmithKline, we suspect that illegal activity such as drug-dealing, and the resultant violence, would be reduced dramatically.

This reduces transfers from wealthier communities, who will have to pay for less law enforcement, perhaps helping to empower and create more desirable political classes. Implicit in Correction’s understanding of the author’s reference to a desirable political class is one that does not depend on the Rothbardian “gang of thieves writ large,” viz., the government.

2) Drugs have differential addition rates. People who are easily addicted and were previously were not exposed to drugs will now have easy access to them. They will subsequently consume the drugs and become addicted.

Corrections does not dispute the idea that people have differential addiction rates. Indeed, it supplements the idea of differential treatment effects we expounded upon in a previous post.

We do, however, dispute the characterization that people who were previously not exposed to drugs will now have easy access to them. In the reading of Corrections, a very large proportion of the United States currently has access to crack cocaine, for instance. They may buy crack cocaine at some price. The question is in what form they pay the price. Corrections conjectures that most of the author’s potential users would pay in the form of search costs, rather than dollars. This can be translated into dollar form, of course.

Why would we assume that people who are easily addicted and have easy access to a product would become addicted? If these individuals know their propensity to become addicted, then they have the most to lose from trying before addiction. We should therefore see these very people shy away from drug use. We should expect to observe tests for whether or not someone has the propensity to become addicted. In the absence of such tests, we might expect the proper incentives to exist to develop them. In the absence of the possibility of such tests, one would expect risk-averse consumers to shy away from the product in general, as large swaths of the non-chipping population likely do for readily available drugs such as crack cocaine.

Whether or not one accepts this previous point, the first point remains: translate search costs into tax costs and it would appear the same costs from suburban individual’s point of view.

We might add that addictive substances such as crack cocaine were a technological advancement on cocaine. It allowed for small cheap, unobtrusive, mass distribution in a way cocaine did not, a point lifted from Roland Fryer, Paul Heaton, Steven Levitt, and Kevin Murphy’s 2005 NBER working paper “Measuring the Impact of Crack Cocaine.” It is not immediately clear whether or not this phenomenally destructive drug would have been as prevalent as it was were cocaine itself not illegal. On the one hand, cocaine is an input into crack cocaine production. On the other hand, cocaine is a substitute to crack cocaine itself, one whose competitive availability is likely increased much more than crack cocaine’s, in light of crack’s popularity being in part due to cocaine’s inefficient illegal distribution system.

3) Student1776 conjectures “People who are addicted do continue to show some level of "rational" behavior in the sense of price responsiveness but addicts are by the nature of the disease incompletely rational. Addicts will engage in extreme and irrational activity including violence and law breaking at felony levels.”

Corrections does not see violence and law breaking at felony levels as an irrational behavior. Take, for example, Lawrence Katz, Steven Levitt, and Ellen Shustorovich’s 2003 American Law and Economics Review article “Prison Conditions, Capital Punishment, and Deterrence”. The homicide rate within a state is negatively impacted by higher within-prison death rates (from murders, illness and AIDs, poor conditions). Indeed, the impact of one additional prison death ranged from -0.1 to -0.8 fewer homicides across the author’s specifications.

Murder, rape, robbery, aggravated assault with a firearm, and burglary of residence are not excluded from the list of crimes for which sentence enhancements significantly change behavior. Daniel Kessler and Steven Levitt found, in their 1999 Journal of Law and Economics article “Using Sentence Enhancements to Distinguish between Deterrence and Incapacitation” that those crimes declined by four percent more than California’s non-enhanced crimes, compared to the difference in decline of the same crimes in other states (without sentence enhancements) and their comparable crimes (a difference-in-difference-in-difference model).

To use the same author a third time, in the Journal of Political Economy (1998) Steven Levitt’s paper “Juvenile Crime and Punishment” shows that not only are juveniles likely deterred by differential sentences, but that an increase in the relative punitiveness of adult crimes compared to juvenile crimes causes decreases in crime when juveniles reach the age of majority. This comparison, comparable to a regression discontinuity comparison, indicates that juveniles around the age of majority appear to be making their criminal decisions based on sentences—-another rational act.

Corrections sees criminals as behaving rationally—-if not during their crimes (say, during a drug-induced state), then in the decisions leading up to the crime (the decision to become intoxicated).

4) It is also noted that if taxation is raised to too high a level then the taxation itself will be surmounted and we will have just created a new kind of illegality. (Not unlike the current cigarette smuggling industry).

Corrections concurs. We see the result as only a partial privatization. If this is the case, then at the limit legality will change nothing because the tax will be too high and the market will remain a black market. In reality, Corrections expects that a portion of the market will be legal and taxed. To take the author’s example, we posit that New York spends vastly less on enforcement and gains vastly more revenue from cigarettes by making them legal and taxing them than it would by making them illegal and paying to enforce the law (rather than be paid).

Thursday, January 21, 2010

Researchers Find Study of Medical Marijuana Discouraged

New York Times article "Researchers Find Study of Medical Marijuana Discouraged" (January 18th, 2010) propagates a mistake in analyzing the impact of any drug on a population. In this case, the Times fails to report on possible treatment-response heterogeneity.

But there is no good evidence that legalizing the smoking of marijuana is needed to provide these effects. The Food and Drug Administration in 1985 approved Marinol, a prescription pill of marijuana’s active ingredient, T.H.C. Although a few small-scale studies done decades ago suggest that smoked marijuana may prove effective when Marinol does not, no conclusive research has confirmed this finding.

And Marinol is no panacea. There are at least three medicines that in most patients provide better relief from nausea and vomiting than Marinol, studies show.

Not all individuals are the same. Individuals have different reactions to different drugs. A drug may have phenomenal effects on twenty percent of the population it works on, while being no different than placebo for the other eighty percent.

Let's imagine a world in which each of the three medicines mentioned in the quote the Times exist, and marijuana is also a potential drug. Let us further imagine that there are four types of responders. Responders who respond to all three drugs but not marijuana, responders who respond only to Drug I and Drug III, responders who only respond to Drug I and Drug II, and responders who only respond to marijuana. This setup is displayed graphically below (click to enlarge), where a "1" denotes effective treatment, and a "0" denotes ineffective treatment.


From this we can see that, if we had a random sampling of all four people types in our drug testing  and assuming each is of equal size (unnecessary for the point, but convenient), then we should see that Drug I is "more effective for most of the population" than Drug II and Drug III, which are in turn "more effective for most of the population" than marijuana.

However, any discerning eye would see that keeping only the three "most effective" drugs offers no alternative for Person Type IV.  The Drug/Person-Type matrix is not of full rank--some individuals are left with nothing.  One might even notice that Drugs II and III are not even necessary, they are redundant, while marijuana is not.

In the above scenario, with treatment-response heterogeneity in the population, relative average effectiveness of a drug is not nearly as important as the population-specific average, and the existence of alternatives within population.