The Fugitive: Evidence of Public versus Private Law Enforcement from Bail Jumping, by Alexander Tabarrok and Eric Helland

Alexander Tabarrok linked to his paper with Eric Helland from the Journal of Law and Economics titled The Fugitive: Evidence of Public versus Private Law Enforcement from Bail Jumping the other day and I asked him to email me the PDF, which I just noticed is online, although it might not be the same version.

I found the introduction and conclusion sections to be the easiest parts to understand because I am not familiar with the technical details of propensity scoring or matching techniques. However, reading the explanations for why certain techniques were used over others is very accessible. I will attempt to highlight what I found most interesting and briefly describe the method, as best I understand it, for the skeptical.


This thirty page paper deals with the following question: What factors effect whether a defendant for a felony will (a) fail to reappear in court after being released for bail and (b) remain a fugitive for a substantial length of time, over one year in particular. Obviously there are many variables, but this paper focuses on how the bail was paid, rather than the bail level (price) as has been the case in most previous studies. There are a number of methods available: deposit bonds, cash, commercial bail (surety bonds), and release on their own recognizance.

The dominant forms of release are by surety bond, that is, release on bail that is lent to the accused by a bond dealer, and nonfinancial release. Just over one-quarter of all released defendants are released on surety bond, and a very small percentage pay cash bail or put up their own property with the court (less than 5 percent combined); most of the rest are released on their own recognizance or on some form of public bail (called deposit bond) in which the defendant posts a small fraction, typically 10 percent or less, of the bail amount with the court. [p. 2]

I found the history of the bail system and the powers of private bail bond dealers to be fascinating:

Although money bail is still the most common form of release, money bail and especially the commercial surety industry have come under increasing and often virulent attack since the 1960s. 7 Bail began as a progressive measure to help defendants get out of jail when the default option was that all defendants would be held until trial. In the twentieth century, however, the default option was more often thought of as release, and thus money bail was reconceived as a factor that kept people in jail. In addition, the greater burden of money bail on the poor elicited growing concern. 8 As a result, significant efforts were made, beginning in the 1960s, to develop alternatives to money bail, and four states—Illinois, Kentucky, Oregon, and Wisconsin— have outlawed commercial bail altogether. [p. 3-4]

On the power of the bounty hunters…

If a defendant does fail to appear, the bond dealer is granted some time, typically 90—180 days, to recapture him before the bond dealer’s bond is forfeited. Thus, bond dealers have a credible threat to pursue and rearrest any defendant who flees. Bond dealers report that just to break even, 95 percent of their clients must show up in court. 16 Thus, significant incentives exist to pursue and return skips to justice.

Bond dealers and their agents have powerful legal rights over any defendant who fails to appear, rights that exceed those of the public police. Bail enforcement agents, for example, have the right to break into a defendant’s home without a warrant, make arrests using all necessary force including deadly force if needed, temporarily imprison defendants, and pursue and return a defendant across state lines without the necessity of entering into an extradition process. 17 [p. 5]

The authors make the case that the bond dealers have both a great incentive to bring their claims to court and have more power to do so. These factors should result in lower rates of failure to appear and lower fugitive rates.

The Method

Of course, I am a bit unsure if I can accurately describe the method, so if this is wrong, tell me, or if you disagree with the results and the method, read the paper for yourself.

Basically, the idea is to take a large sample of data collect by the U.S. Department of Justice on the conditions being studied and try to identify individuals with similar situations but different “treatments.” Here, it seems that “treatment” refers to what method of bail was used.

Ideally, in a treatment evaluation we would like to identify two outcomes: one if the individual is treated, YT, and one if no treatment is administered, YNT . The effect of the treatment is then YT – YNT. But we cannot observe an individual in both states of the world, making a direct computation [...] impossible. 28 All methods of evaluation, therefore, must make some assumptions about “comparable” individuals. An intuitive method is to match each treated individual with a statistically similar untreated individual and compare differences in outcomes across a series of matches. Thus, two statistical doppelgangers would function as the same individual in different treatments. [p. 7]

After codifying the data and matching each individual with their twin, a propensity score is calculate to codify the effect of each different treatment. Certain tests are made on this data to ensure that there have not been significant errors made:

Matching is a powerful and flexible tool, but it is not a research design that magically guarantees the identification of causal effects. In this section, we test for robustness and attempt to rule out the potentially confounding effects of unobservable characteristics. We focus on two identification strategies; a number of alternative strategies, described briefly below, are developed in the working paper. [p. 22-23]

This should have provided a delicious appetizer for someone interested in where the results come from.


I will quote the short conclusion in full:

When the default was for every criminal defendant to be held until trial, it was easy to support the institution of surety bail. Surety bail increased the number of releases relative to the default and thereby spared the innocent some jail time. Surety release also provided good, albeit not perfect, assurance that the defendant would later appear to stand trial. When the default is that every defendant is released, or at least when many people believe that “innocent until proven guilty” establishes that release before trial is the ideal, support for the surety bail system becomes more complex. How should the probability of failing to appear and all the costs this implies, including higher crime rates, be traded off against the injustice of imprisoning the innocent or even the injustice of imprisoning the not-yet-proven guilty? We cannot provide an answer to this question, but we can provide a necessary input to this important debate.

Defendants released on surety bond are 28 percent less likely to fail to appear than similar defendants released on their own recognizance, and if they do fail to appear, they are 53 percent less likely to remain at large for extended periods of time. Deposit bonds perform only marginally better than release on own recognizance. Requiring defendants to pay their bonds in cash can reduce the FTA rate similar to that for those released on surety bond. Given that a defendant skips town, however, the probability of recapture is much higher for those defendants released on surety bond. As a result, the probability of being a fugitive is 64 percent lower for those released on surety bond compared with those released on cash bond. These finding indicate that bond dealers and bail enforcement agents (bounty hunters) are effective at discouraging flight and at recapturing defendants. Bounty hunters, not public police, appear to be the true long arms of the law. [p. 26]

Further Reading

Apart from the last sentence of the conclusion, the paper is very free from moralizing or throwing down of the gauntlet with regards to this version of private law enforcement. Outside the paper, however, Prof. Tabarrok has written in this way on the issue.

Bring on the Bounty Hunters at the site of the Independent Institute:

It looks impressive when a judge bangs his gavel and orders someone’s arrest. Criminals, however, aren’t fooled. They know the probability that a warrant will ever be served is minimal.

According to an investigative report by the San Francisco Chronicle, more than 2.5 million arrest warrants are currently outstanding in the State of California. Many of the arrest warrants are for misdemeanors, but thousands of arrest warrants for homicide, kidnapping, sexual assault and other serious crimes also languish unserved.

Local, state and federal law enforcement agencies often don’t even try to serve warrants. Instead, they ignore the public’s right to safety and simply wait until the suspect is arrested for some other crime. More outrageously, many of these suspects are released on their own recognizance time and time again. As a result, multiple arrest warrants for failure to show up at trial are not uncommon.

At the Marginal Revolution, he wrote about a talk he gave to the California Bail Agents Association.

Lisa Margonelli mentioned the paper in an article on

Prof. Tabarrok has a category here on makeoutcity and has a blog, the Marginal Revolution.