Many New Yorkers who are summoned to court for a range of minor infractions—from littering to disorderly conduct—don’t realize that not appearing in court on their designated date automatically sets in motion a warrant for their arrest. In 2014, 41% of the approximately 320,000 people issued a citation for a violation or low-level misdemeanor in New York did not take the required responsive action. Increasing court appearance rates would benefit both citizens and the city–it removes an otherwise significant burden on the individual and reduces unnecessary administrative and enforcement costs for the city.

We took a behavioral approach to exploring this problem, believing it unlikely that so many people were intentionally dismissing the importance of appearing in court, but rather that they didn’t have a strong grasp of the repercussions and had trouble fitting this one-time event into their daily lives. That’s why we partnered with the Mayor’s Office of Criminal Justice, the New York State Office of Court Administration, and the New York City Police Department to redesign the summons form to better prepare people to attend their court date.

The new form more prominently displays the time, date, and location of court appearances as well as consequences for not showing up to court. We know from behavioral science that the way information is presented affects behavior, and that held true in this context: a study of the new form’s impact, conducted by the University of Chicago Crime Lab, revealed that it reduced rates of missed court appearance by 13%.

In addition to redesigning the summons form, we partnered with the University of Chicago’s New York Crime Lab to design text messages to be sent recipients who supplied phone numbers on the form. Well-designed reminders can help people plan around their daily responsibilities (such as work and child care) to ensure they can make it to their appointment. In this case, the most successful reminders, which combined information about the consequences of not showing up to court, what to expect at court, and plan-making elements, reduced rates of missed court appearance by 26%. These results are in addition to the gains already realized from the summons form re-design.

The NYPD is now exclusively using the new forms for all criminal court summons, and the Office of Court Administration will send text messages to all summons recipients whose phone number is reported on the summons form. Combining these two cost-effective interventions and scaling them to reach as many people as possible could prevent tens of thousands of warrants from being issued each year—creating a tangible impact in the lives of many New Yorkers.

These promising results and the ongoing work lays a foundation for applying behavioral insights to more issues within public safety and justice, and it demonstrates that solutions based on behavioral insights can benefit the court system, law enforcement, and the public.

We are grateful for the generous support of this work by the Laura and John Arnold Foundation, the John D. and Catherine T. MacArthur Foundation, and the Abdul Latif Jameel Poverty Action Lab (J-PAL). To learn more about how behavioral design can be used to improve criminal justice outcomes, read our full report of this work.