Recently in Studies Category

As Bill noted earlier today, the theme of the opening day of the Republican National Convention is Make America Safe Again.  Is America unsafe?  Is a change of direction needed?  Consider two graphs (click on them for larger views):


Biased fact-checkers have assailed Donald Trump's emphasis on law and order, quoting experts citing the data in the first graph, as noted in this post.  Yes, crime has fallen since 1993.  It is half what it was at the peak, although still far above the golden years of the Ozzie and Harriet era.  You don't see an uptick at the end of the graph, do you? 

But look at the scale.  The official numbers are notoriously slow in coming out.  The scale ends at 2014.  What about the last year and a half?

The graph on the right represents crime in the first quarters of 2015 and 2016.  It shows violent crime up in every category and a nearly seven percent jump in a single year.  These numbers are from the Major Cities Chiefs Association, a recent entrant in the crime statistics business.  Their only prior numbers are for 2014 v. 2015, which also showed an increase in all categories except robbery.  The major cities included cannot be assumed to be representative of the country, but they include the places where a large portion of our people live and work.

Seven percent in one year is a dramatic jump, and combined with a broad increase, although smaller, in 2015, it is likely not a fluke.  The major increase in California, noted here, a state that gone full bore in softening its approach to crime, further supports the idea that a general softening is a significant contributing cause.

While I might quibble with the wording of the theme, the renewed attention to law and order is appropriate and welcome.  We must not forget and repeat the errors of the past.

Donald Trump said "crime is rising," and PolitiFact rated that statement "Pants on Fire."  Eugene Volokh looks into it.

It seems that PolitiFact based its rating on the fact that crime has been on a long downward trend overall for the last 25 years.  Volokh writes,

I don't find this a persuasive defense. If the original PolitiFact post had said something like, "The violent crime rate has plummeted in the past 25 years, and while it may have been increasing in the last year and a quarter, that could easily be an anomaly, and our data on that are just preliminary and may not be sound," I would have thought it a sensible criticism of Trump's assertion. We should indeed be cautious about data that are limited to one year, or (as with the 2016 first-quarter data) to a subset of jurisdictions. There is some degree of short-term variation within any long-term trend; data from a year and change aren't really enough to tell whether 1) the long-term violent crime decline has been reversed, or 2) the year was just an anomaly and the decline will continue, or at worst, the violent crime rate will remain flat. For instance, the violent crime rate increased in 2005 and 2006, but those proved to be just small blips in an otherwise substantial decline.
The previous post noted the increase in homicide in California in 2015 over 2014.  The increase extends to every category of crime tracked except burglary, according the annual Crime in California report, also released today by the Bureau of Criminal Information and Analysis.  Annual changes in rates of reported crime per 100,000 population are:

Agg. Assault+8.1%
Auto theft+12.5%

The number for rape is also up sharply, but the extent to which that is an increase in crime versus a broadened definition of which sexual assaults are counted in the category is uncertain.

None of this should surprise anyone who has been paying attention.  After Realignment, we had numbers in the next few years that fluctuated but overall were considerably worse than the national numbers.  See this post.  Auto theft in particular spiked after Realignment made it a never-prison offense.  See here and here.  After Proposition 47, anecdotal information from law enforcement has been steadily rolling in.  Now we see confirmation in statewide numbers.

These soft-on-crime changes are disasters, and people are paying for them in blood and hard-earned property.

Murders Spike 10% in California

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The number of murders in California jumped nearly ten percent from 2014 to 2015, according to the annual Homicide in California report released today by the Bureau of Criminal Information and Analysis. A total of 1861 people were murdered in state in 2015, up from 1697 in 2014, a 9.7% increase.  Due to an increase in population, that works out to a 9.1% increase in murders per 100,000 population.
Time to bring out the elephant in the living room again.  As described by Wikipedia:

"'Elephant in the room' or 'Elephant in the living room' is an English metaphorical idiom for an obvious truth that is going unaddressed. The idiomatic expression also applies to an obvious problem or risk no one wants to discuss.

"It is based on the idea/thought that an elephant in a room would be impossible to overlook."

Lisa Marie Pane and Don Babwin have this story for Associated Press.

CHICAGO -- Violent crimes - from homicides and rapes to robberies - have been on the rise in many major U.S. cities, yet experts can't point to a single reason why and the jump isn't enough to suggest there's a trend.

Still, it is stumping law enforcement officials, who are seeking a way to combat the problem.

"It's being reported on at local levels, but in my view, it's not getting the attention at the national level it deserves," FBI Director James Comey said recently. "I don't know what the answer is, but holy cow, do we have a problem."

You have to get down to the 15th paragraph before the Ferguson Effect is even mentioned, and it is immediately followed by a dismissive comment by the lacking-a-better-explanation expert.  The ongoing efforts to dismantle the highly successful tough-on-crime movement of the past several decades -- ignoring history in order to repeat it -- is not mentioned at all.

The anti-punishment and anti-police crowds (overlapping but not equal sets) have been on a roll for several years now.  When the results that persons of sense warned would follow do follow, the likely causal connection must be ignored or dismissed.

Another Hidden Cost of Crime

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Unfortunately, some people on the conservative side of the political aisle have jumped on the "let-em-out" bandwagon because they see that as a way to reduce government budgets.  Looking at costs to government alone, however, is not the correct way to measure costs of alternative courses of action to society as a whole.  When government fails in its fundamental obligation to protect people from crime, it imposes costs on the victims, a kind of "crime tax" that falls heavily, partly at random, but disproportionately on people of modest means.  Quantifying the cost of crime to victims is a tricky business in many ways, and one of the ways is that much of the cost is hidden.  Science Daily has this article on a hidden cost that has been overlooked to this point:

In a recent paper published in the Journal of Development Economics, researchers Professor Marco Manacorda (Queen Mary University of London) and Dr Martin Foureaux Koppensteiner (University of Leicester) focused on evidence from the exposure of day-to-day violence in Brazil by analysing the birth outcomes of children whose mothers were exposed to local violence, as measured by homicide rates in small Brazilian municipalities and the neighbourhoods of the city of Fortaleza.

The team estimated the effect of violence on birth outcomes by comparing mothers who were exposed to a homicide during pregnancy to otherwise similar mothers residing in the same area, who happened not to be exposed to homicides.

The study found that birthweight falls significantly among newborns exposed to a homicide during pregnancy and the number of children classified as being low birthweight increases -- and that the effects are concentrated on the first trimester of pregnancy, which is consistent with claims that stress-induced events matter most when occurring early in pregnancy.

Evidence Mounts on Crime Spikes

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Many people   -- including law enforcement officials, bloggers here, and Heather MacDonald at the Manhattan Institute -- have been raising alarms that increasing numbers of innocent people are being needlessly victimized due to ill-considered policy changes (e.g., California's "realignment" and Prop. 47) and the "Ferguson Effect" of police holding back as they come under hyper-scrutiny.  Soft-on-crime apologists have responded that the data are too tentative and too anecdotal to draw such conclusions.  That answer did have some validity initially, but it wears increasingly thin as data accumulate.

In Chicago, the local variant of the Ferguson Effect might be called the McDonald Effect.  The number crunchers at FiveThirtyEight (who definitely do not lean conservative) have concluded that the numbers have reached the threshold that they can't be brushed off like that any more.  Rob Arthur and Jeff Asher have this post.
Some of the best information we have in social sciences comes from longitudinal studies, where people are followed and data gathered over a long period of time.  Such studies are more likely to give us definitive answers than "snapshot" correlational studies that look at a sample at one time and merely tell us that certain factors tend to go together in members of the sample.

The problem with longitudinal studies, of course, is that they necessarily take a very long time to do.  Some of the best work has come out of New Zealand.  Magdalena Cerda, Terrie Moffitt, et al. have this article in Clinical Psychological Science on results from the Dunedin Longitudinal Study on the long-term effects of persistent marijuana use.  Here is the abstract:

With the increasing legalization of cannabis, understanding the consequences of cannabis use is particularly timely.  We examined the association between cannabis use and dependence, prospectively assessed between ages 18 and 38, and economic and social problems at age 38. We studied participants in the Dunedin Longitudinal Study, a cohort (N = 1,037) followed from birth to age 38. Study members with regular cannabis use and persistent dependence experienced downward socioeconomic mobility, more financial difficulties, workplace problems, and relationship conflict in early midlife. Cannabis dependence was not linked to traffic-related convictions.  Associations were not explained by socioeconomic adversity, childhood psychopathology, achievement orientation, or family structure; cannabis-related criminal convictions; early onset of cannabis dependence; or comorbid substance dependence. Cannabis dependence was associated with more financial difficulties than was alcohol dependence; no difference was found in risks for other economic or social problems.  Cannabis dependence is not associated with fewer harmful economic and social problems than alcohol dependence.

The New Data on Eyewitness Testimony

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The current issue of the Monitor has a short article on some new data regarding eyewitness testimony.  For many years, various psychological experts have insisted that sequential lineups are vastly superior to simultaneous lineups.  Now, perhaps, the reverse is true:

By some estimates, around a third of law enforcement agencies in the United States now use the sequential format, says John Wixted, PhD, a psychologist at the University of California, San Diego. But, he says, that switch might have been a mistake.

Wixted is one of several scientists, along with Clark and Scott Gronlund, PhD, a psychologist at the University of Oklahoma, who have championed a statistical method called receiver operating characteristic (ROC) analysis, a method widely used in other fields to measure the accuracy of diagnostic systems.

Using that analysis, sequential lineups don't appear to be beneficial -- and might lead to slightly more misidentifications than simultaneous lineups, Gronlund and Wixted have reported (Current Directions in Psychological Science, 2014). The problem, they say, is that previous analytical methods confounded accuracy with a witness's willingness to choose a suspect. In other words, sequential lineups seem to make people less likely to make a choice at all. But when they do pick a suspect, they might be at greater risk of making the wrong choice. "It turns out sequential lineups are inferior," says Wixted.

And what about eyewitness confidence?

For many years, researchers didn't think an eyewitness's confidence revealed much about his or her accuracy in identifying a suspect, says Wixted. A confident eyewitness could be just as likely to get the ID right -- or wrong -- as a less confident witness. But in the last two decades, numerous analyses have converged on the fact that eyewitness confidence is actually a strong indicator of accuracy.

Stats Matter

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The Ferguson effect is undoubtedly being downplayed by the left.  Heather Mac Donald has this piece in the City Journal addressing the way researchers have tried to obscure its existence.  The subject of the piece is a recent paper published in the Journal of Criminal Justice and authored by four University of Colorado Boulder researchers and sociologist David Pyrooz, in which they "created a complex econometric model that analyzed monthly rates of change in crime rates in 81 U.S. cities with populations of 200,000 or more."  Some of the their findings:

The researchers found that in the 12 months before Michael Brown was shot in Ferguson, Missouri--the event that catalyzed the Black Lives Matter movement--major felony crime, averaged across all 81 cities, was going down. In the 12 months after Brown was shot, that aggregate drop in crime slowed down considerably. But that deceleration of the crime drop was not large enough to be deemed statistically significant, say the criminologists. Therefore, they conclude, "there is no systematic evidence of a Ferguson Effect on aggregate crime rates throughout the large U.S. cities . . . in this study."

Mac Donald clarifies:

[T]he existence of a Ferguson effect does not depend on its operating uniformly across the country in cities with very different demographics. When the researchers disaggregated crime trends by city, they found that the variance among those individual city trends had tripled after Ferguson. That is, before the Brown shooting, individual cities' crime rates tended to move downward together; after Ferguson, their crime rates were all over the map. Some cities had sharp increases in aggregate crime, while others continued their downward trajectory. The variance in homicide trends was even greater--nearly six times as large after Ferguson. And what cities had the largest post-Ferguson homicide surges? Precisely those that the Ferguson effect would predict: cities with high black populations, low white populations, and high preexisting rates of violent crime.
CalNonCalCrimeChanges2014_2015.gifAs noted previously on this blog, the FBI recently announced the Preliminary Semiannual Uniform Crime Report covering the first half of 2015 for cities over 100,000.  I have totaled the crime counts for violent and property crimes for 2014 and 2015 and computed the percent changes for California cities versus cities in other states.  Click on the graph for a larger view.

California has (1) court orders overriding state law to release prisoners because of overcrowded conditions caused by the Legislature's failure to build enough prison space, (2) the "realignment" program moving prisoners from state prison to overcrowded county jails where they are either released or push out prisoners who would otherwise be in jail, and (3) Proposition 47, which reduced many felonies to misdemeanors.  Between these measures, the state has seriously softened its approach to crime and put many criminals on the street who would otherwise be in custody.  Although other states are taking more modest measures to reduce prison populations, nowhere else do we see this headlong rush to push criminals out the gates.  One would expect, then, that California would have much worse results than other states, and that is exactly what we see.

What is Governor Brown's plan?  Push even more criminals onto the streets. 

Murders Up 6.2%, FBI Data Show

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Official crime statistics are slow to confirm what common sense tells us is likely to happen and what anecdotal evidence tells us is happening.  There is a lag between cause and effect and another lag between effect and the official statistics.  But eventually the facts, "stubborn things," do come in.

Devlin Barrett has this article in the WSJ, with the above headline in the print version (slightly different online).

Murders rose 6.2% in the first half of 2015, according to preliminary crime data released Tuesday by the Federal Bureau of Investigation, figures that are likely to further fuel the current political debates about crime, policing and sentencing.

Violent crime overall increased 1.7%, the FBI found, while property crimes decreased 4.2%, compared with the first six months of 2014. Police chiefs from around the country had warned about an apparent surge in recent months.

Notes on Crime Statistics

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Carl Bialik has this post at 538 Blog on crime statistics and why they can be confusing and manipulated.  It's a useful post on the technical aspects, but the "spin" aspect of it is annoying.  Bialik tries to soft-pedal the increase in homicides.  A 14% jump in a single year is huge.

Bialik says, "For what it's worth, homicides are up -- though probably by less than what you've read."  What's with the "probably"?  Is he implying that most news media have exaggerated the increase?  From what I have read, most media are fully complicit in the soft-peddling.

"So-called justifiable homicides don't count toward the FBI definition."  So-called?  They are called that because they are that.  Would you point at an oak tree and say it is a "so-called oak"?

Bialik discusses the problem of crimes being defined differently in different jurisdictions, which is indeed a huge problem in crime statistics.  (It's even worse when you go international.)  He talks about the NYPD's reporting of "shootings" and the FBI's UCR category of "aggravated assault."  He quotes a criminologist saying (correctly), the latter is more deserving of confidence.  Then he tosses in, "Unfortunately, the FBI doesn't separate assaults by firearm from other assaults for individual cities in the data it reports."  Why unfortunate?  If you need to choose between classifying assaults by harm caused and classifying them by weapon used, it seems to me that harm caused is by far the more important.  Ideally, you could classify them both ways, but resources limit what you can do, so the ideal is rarely achieved.
Here's a follow-up on my Boxing Day post.  That big city murder increase dismissed as a mere 11% in a single year in the Brennan Center's preliminary figures turns out to be 14.6% in the final figures, according to this press release.  That is nearly one in seven.  And what could cause this?

The preliminary report examined five cities with particularly high murder rates -- Baltimore, Detroit, Milwaukee, New Orleans, and St. Louis -- and found these cities also had significantly lower incomes, higher poverty rates, higher unemployment, and falling populations than the national average.
"There are none so blind as those who will not see."  These are also cities where the police are under severe attack.

Simultaneous v. Sequential Lineups

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One thing we know from studying studies is that you should not make radical changes based on a single study but rather wait for the result to be confirmed by other studies.  You don't know how "robust" a result is until an issue has been studied multiple ways by multiple researchers.  How many times would you have stopped and restarted drinking coffee if you went with every study that came along?

A while back there was some research that indicated that sequential lineups -- where the witness looks at suspects or pictures one at a time -- were far better than simultaneous ones where the witness looks at a group at once.  There was a rush to codify this preference into rigid requirements.  Well, that may not be right.  Bradley Fikes reports in the San Diego Union Tribune on a study indicating, among other things "simultaneous lineups were, if anything, diagnostically superior to sequential lineups. These results suggest that recent reforms in the legal system, which were based on the results of older research, may need to be reevaluated."

Another important finding is that the witness's confidence at the first observation is an important indication of accuracy, much more so than the witness's demeanor at trial that juries must usually go on.

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