Category: Studies and Statistics

Study Finds No Effect of Gun Buybacks

The Philadelphia Inquirer has this op-ed by Temple University Professor Jerry Ratcliffe and grad student Marc Huffer. Their recently published study adds to the evidence that gun buyback programs are just for show and have no measurable effect on gun crimes. What’s the problem? The programs buy back the wrong guns. The guns the programs buy are brought in by law-abiding folks, while the criminals keep theirs. “Tellingly, Philadelphia’s Office of Forensic Science has never found a National Integrated Ballistic Information Network link to a crime with any gun surrendered in the city’s gun buyback program. Clearly, buyback firearms are not the ones causing such misery in the city.”

That’s consistent with what common sense told us all along, but “never” is a stronger result than I expected. Continue reading . . .

Alarming Rise in Carjacking by Juveniles in DC

Liam Bissainthe has this post at Liberty Unyielding, reporting that carjacking in DC is up 600% over 2019. The post cites this report from WTOP on October 3, reporting that as of that date there had been 750 carjackings in 2023, 75% of them involving guns. Nearly two-thirds of the persons arrested for carjacking to that date were juveniles.

Why do so many DC juveniles commit this violent crime?

Continue reading . . .

Retail Crime Survey

Surveys of crime are worth keeping an eye on, as they help compensate for a major deficiency in official crime statistics. The official stats are generally “crimes known to the police.”  These crimes are undercounted when people don’t bother to report the crimes, and the nonreporting rate tends to increase when policies are adopted that lead people to believe that the police won’t do anything if they do report.

The National Retail Federation has this report on its 2023 Retail Security Survey. Among the results reported are the metropolitan areas identified by retailers as most affected by organized retail crime:

Continue reading . . .

Crime in the United States and California

Some years ago, we began tracking the trends in crime in California versus the country as a whole. California has been more aggressive than most states in the “criminal justice reform” movement, a euphemism for reducing the consequences of crime to criminals. See prior posts on the archive blog here and here. (See tech note below if you have difficulties.)

With the release of the 2022 national crime data (see this post), it seemed like a good time to update the data.

Graph of US v California Violent Crime

Continue reading . . .

CA Violent Crime Increases as Arrests Decline

Fresh FBI data for 2022 indicate that nationally the rate of violent crime dropped slightly.  In California violent crime increased by 5.7% with   aggravated assault accounting for 67%.  Property crime nationally increased by 7.1% while California’s increase was 5.9%.  Matt Delaney of The Washington Times reports that motor vehicle theft continued to increase both nationally and in California, where thefts have increased by 31.6% since 2019.  A report by the Public Policy Institute of California (PPIC) found that the California counties with the sharpest increases in violent crimes were the bay area counties of Contra Costa, San Mateo and San Francisco.  Sacramento, Riverside, Alameda and Orange counties also saw significant increases.  Major property crime increases were seen in Fresno, Alameda, Santa Clara, Orange and San Bernardino Counties.  One positive note, homicides were down by 6.1% after significant increases in 2020 and 2021.

Continue reading . . .

Regression 101 and Discrimination

Do the usual explanations of statistics, and especially regression analysis, make your eyes glaze over? If so, join the very large club. Help is here from the Manhattan Institute. George Borjas has this article in the City Journal giving a nontechnical description of the use of regression in claims of discrimination, its difficulties, and why different experts can find different results from the same raw data.

The article discusses claims that Harvard discriminated against Asian applicants, the subject of a recent Supreme Court decision. The same principles apply to discrimination claims in criminal cases, including McCleskey v. Kemp (1987) and states with misguided and misnamed Racial Justice Acts. Continue reading . . .

Latzer and Mangual: The Myths of Mass Incarceration and Overpolicing

Here is a very worthwhile event, available online at the Heritage Foundation. Barry Latzer and Rafael Mangual will speak on the topic above at noon EST on Thursday, January 26. We have quoted both Latzer and Mangual often on this blog. Our friend Cully Stimson is the host.

In criminal justice, as the old saying goes, it’s not what we don’t know that gets us in trouble; it’s what we know for a fact that just is not so. We can expect Latzer and Mangual to expose many “woke” myths at this event.

Sentencing Length and Recidivism: A Review of the Research

We previously announced a working paper, Sentence Length and Recidivism: A Review of the Research, in May 2021 and announced an update last June. We are pleased to announce that the review has now been published in a peer-reviewed journal, Federal Sentencing Reporter, in the October issue. (Vol. 35, No. 1) The permanent link to the published version is https://doi.org/10.1525/fsr.2022.35.1.59. The paper is also available on CJLF’s website.

Here is the abstract:

In response to prison overcrowding concerns in recent years, many U.S. officials have undertaken efforts to reduce sentence lengths for certain crimes. However, it is unclear how these changes affect recidivism rates. Among the research on incarceration and recidivism, the majority of studies compare custodial with noncustodial sentences, while fewer examine the impact of varying incarceration lengths. This article reviews the research on the latter. Overall, the effect of incarceration length on recidivism appears too heterogeneous to draw universal conclusions, and findings are inconsistent across studies due to methodological limitations. For example, many study samples are skewed toward people with shorter sentences while others include confounds that render results invalid. Of the studies reviewed, some suggested that longer sentences provide additional deterrent benefits in the aggregate, though some studies also had null effects. None suggested a strong aggregate-level criminogenic effect. We argue that a conclusion that longer sentences have a substantial criminogenic effect, large enough to offset incapacitative effects, cannot be justified by the existing literature.

That last sentence is important. Continue reading . . .

Is Crime in San Francisco Worse Than NYC?

Responding to MSNBC interviewer’s statement that New York City residents “don’t feel safe in this town,” and are “worried we could become San Francisco,” the state’s newly-elected Governor Kathy Hochul said NYC “will never be San Francisco.”  Mallory Monench of the San Francisco Chronicle reports that Hochul went on to say that the Big Apple was successfully fighting crime, with homicides and shootings down dramatically from last year.  While the two cities have vastly different populations, on overall crime they are generally comparable.   Homicides are tracking down 14% in New York City compared to last year while they are up in San Francisco by .43%.  But NYC saw dramatic increases in 2020 and 2021, while San Francisco homicides increased only slightly.  Both cities have unacceptable rates of violent crime.  When it comes to property crime Hochul is correct about San Francisco.  The numbers for 2020 show almost three times the rate of property crimes in San Francisco than in New York.  The reporter admits something that most of the media and liberal think tanks ignore, “The number is almost certainly higher in reality since many people don’t report property crime to the police because of the perception that doing so won’t make a difference.”

Continue reading . . .

A Severity-Weighted Index of Violent Crime

In debates over criminal justice policy, people are constantly referring to crime indexes for the question of whether crime is up or down and by how much. But there are problems with the official indexes. One of them is that indexes tend to be dominated by the least serious crime chosen for inclusion in the particular index. Crimes are simply counted, and because the frequency of crimes tends to be inversely related to their severity, the less serious crimes dominate.

For example, the FBI’s index of violent crime includes murder (and voluntary manslaughter), rape, robbery, and aggravated assault. Murder is the most serious, followed by rape, but the other two are much more common. As a result, the violent crime index is largely a measure of robbery and aggravated assault, and it relatively insensitive to changes in the rates of murder and rape.

One alternative is an index with crimes weighted according to their severity. I have seen such indexes in other countries and for some jurisdictions within the United States, but none for the United States as a whole. Here is a first cut at a severity-weighted index of violent crime in the United States. Continue reading . . .