Category: Studies and Statistics

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 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 . . .

Comparing nationwide violent crime estimates: Summary-based vs. incident-based reporting

The FBI released official 2021 crime statistics last month, but the data leaves major gaps in our understanding of national-level crime rates. Unfortunately, the numbers are incomplete this year because 36% of U.S. law enforcement agencies, some of them major cities, failed to submit their crime reports. This is largely because the FBI made major changes to the way that it collects crime data, making the submission process much more complicated. Rather than following the arduous process, many agencies simply declined to participate in last year’s data collection. In comparison, 2020 crime statistics included data from 85% of U.S. law enforcement agencies.

This post briefly reviews agency participation rates and discusses what that means for our current understanding of national-level crime. Then, using data from the years 2017-2020 (all of the years for which data from both systems are available),  I examine whether the two systems produce similar violent crime estimates. 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 . . .

Violent crime is a key issue for U.S. midterm election

Crime has become a big issue in the U.S. midterm elections. According to a recent Gallup poll, crime ranked as the second most important issue among voters, with 71% of registered voters saying it was either “extremely” or “very” important to their vote. This came second after the economy, which 85% of voters said would be extremely or very important to their vote. According to a different Gallup survey released a few weeks ago, more than half of Americans (56%) said there was more crime in their area compared to a year ago. According to Gallup, “That’s up a whopping 11 points from 2021 and 18 points from 2020, and is the highest mark ever measured.” This issue was a concern across party lines, with 73% of Republicans, 51% of Independents, and 42% of Democrats all agreeing that crime is getting worse (in 2020, these percentages were 38%, 38%, and 37%, respectively).

Continue reading . . .

Misconceptions about racial disparities in police investigations: Results from Tucson

Debates about racial inequalities in the criminal justice system have ramped up in the last several years. This has been largely driven by discussions about racially-biased police violence, but many also speculate about disparities in how the police treat crime victims. For example, one common belief is that the thoroughness of police investigations varies based on victim and officer race. But a recent study published in The Journal of Law and Economics (subscription required for access) suggests otherwise, at least in the context of residential burglary.

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 . . .

2021 national crime rates are a mystery as FBI transitions to a new data system

Earlier this month, the FBI released the national-level crime statistics for 2021. According to that data, violent crime, particularly murder, remained a major issue in the United States. Crime remained relatively consistent from 2020 to 2021 with no statistically significant changes between years, though violent crime was still elevated compared to 2019 levels. From 2020 to 2021, national levels of violent crime decreased slightly (-1.0%), largely driven by decreases in robbery (-8.9%). Murders, however, increased (+4.3%). The data is available for download via the Crime Data Explorer, or it can be accessed using a new tool called the Law Enforcement Agency Reported Crime Analysis Tool (LEARCAT). But the data this year may be lower quality than years past, limiting our ability to draw inferences about national-level crime rates.

Policymakers and researchers rely on these data to understand state and national crime trends, but that may be more challenging this year. Unfortunately, the FBI’s plan to modernize its reporting of crime data has not gone according to plan, so it’s hard know how accurate these 2021 estimates are. The new system has advantages over the old system, but it is much more cumbersome and time-consuming to use, which has negatively impacted law enforcement agencies’ willingness to submit their data. And because of these low participation rates, there are huge gaps in nationwide crime statistics for 2021.

Continue reading . . .

Crime trends in California: 2021 rates show increase in violent crime

A new report from the Public Policy Institute of California (PPIC) reviews some of the recently released state-level data on 2021 California crime rates. Once again, it seems like the authors are overselling the fact that crime rates are lower than the 1990s crime peak, although their findings are similar to what I found when I analyzed the data last month. Indeed, crime rates are lower than they were in the 1990s. But keep in mind that the 1990s saw a historic crime peak. If “success” means having crime rates that are lower than the historic peak, then that’s a pretty low bar for success. It’s almost like saying that the 2008 recession wasn’t that bad because it was still better than the Great Depression.

Continue reading . . .

Krasner insists that his policies are “working,” seemingly unconcerned about homicide rates

Over the last several years, the progressive prosecutor movement has grown in popularity, with more and more policy changes reducing penalties for certain crimes. A common theme is for district attorneys to restrict prosecutions for certain offenses, and to reduce the severity of punishments for cases that are prosecuted.

One example is Philadelphia District Attorney Larry Krasner, who has been dismissing more and more cases each year, despite the fact that the city recently reached its highest murder rate in history. He thinks that his approach is “working,” per a recent local news interview (originally reported by Heather McDonald in the Daily Mail and summarized in a CJLF post). In the interview, he incessently denied that his policies have negative consequences and was seemingly unconcerned about the homicide increase.

The sheer fact that homicides have increased in Philadelphia every year of Krasner’s term should be cause for concern. Not surprisingly, a deep dive into the research confirms that Krasner’s policies are at least partially to blame for the increase in homicides in Philadelphia.

Continue reading . . .