Proof-of-Concept Computational Policy Model for TACT

Researchers in CMAC’s Tools against Child Sex Trafficking Project (TACT) are building computational policy models to virtually evaluate and experiment with anti-human trafficking policy options. This project also aims to demonstrate the effectiveness of computational modeling and simulation in analyzing policy proposals. Output data can be used as a measure to determine whether or not a policy is working well.

Using input data from King County, WA, CMAC Postdoctoral Fellow Khatera Alizada built an agent-based simulation model to explore the impact of two law-enforcement strategies a) arresting and prosecuting minor victims of sex trafficking for prostitution charges, and b) arresting and prosecuting buyers who purchase sex from minors. Alizada sought to learn how each tactic effects the rate of child sex trafficking in King County, WA.


The model simulates these two law-enforcement strategies in a virtual society and generates outputs in the form of the number of children trapped in commercial sex trafficking and the number of commercial sex transactions with children. The results show that targeting demand (arresting and prosecuting buyers) reduces child sex trafficking in King County, WA more effectively than targeting supply.

King County, Washington State

Switching law-enforcement focus from supply to demand reduces the number of sex trafficked children by more than 50 percent and the commercial sex purchase by about 1.5 percent per year.

The following graph depicts the percentage difference between purchases in 2009 and purchases in 2015 over the one-year period of the simulation, with 52 one-week time-steps. A positive percentage number indicates that the 2009 number is higher by that percentage than the 2015 number. At the beginning of the year there is little difference, but the difference grows, producing an end-of-year situation in which there are 1.5% fewer purchases in 2015 than in 2009, with a 3.5% decrease in the number of buyers in 2015. Since the simulation runs reflected the policy change from supply-side arrests to demand-side arrests, and since these models are causal and not merely correlational (as statistical models are), researchers know that the change occurs because of the policy shift.

Figure 1. Percentage Difference in Purchases 2009 Vs 2015

Researchers can also use the number of sex trafficked children over the course of one year to evaluate the policy change. The orange line displays the percentage decrease in the count of sex trafficked children in 2015 (with a demand-side focused policy). The positive percentage indicates that in 2009 the number of trafficked children is higher than in 2015. In 2015, the number of children trapped in sex trafficking reduces by more than half.

Figure 2. Percentage Decrease in the Count of Children Trapped in Sex Trafficking 2009 Vs 2015

The results therefore agree that targeting buyers and protecting victims has a more significant impact on overall reduction of commercial sexual exploitation of minors in King County, WA, matching the results of their policy experiment.


In October 2014, King County launched a policy program, Buyer Beware, designed to reduce the demand for purchase of commercial sex online. Its suggested policies shifted the prosecutorial focus from supply side (arresting prostituted people) to demand side (targeting buyers of commercial sex). The Buyer Beware program is committed to running reverse-sting operations on a monthly or bi-monthly basis. A reverse sting operation is when a police officer poses as a prostitute to arrest a buyer.

In 2009, before adopting the Buyer Beware program policies, 53 prostituted minors were charged for prostitution and 2 buyers were charged for buying sex from children. In 2015, 46 buyers were charged for buying sex from children and 0 children were charged for prostitution (Richey 2018). Historically, over 90 percent of those arrested for prostitution in the United States are sellers and fewer than 10 percent are buyers. When comparing the effectiveness of supply-focused versus demand-focused intervention strategies, the empirical evidence suggests that demand-focused law enforcement is more effective in reducing commercial sexual exploitation. For example, in Sweden after prohibiting purchase of sex, prostitution reduced more than 50 percent. There is very little evidence that targeting supply yields more than a temporary suppression or displacement of prostitution.

The 3P Directory: Categorizing Efforts to Combat Human Trafficking in MA

The Tools against Child Trafficking (TACT) project equips anti-trafficking efforts with the necessary resources to accelerate their solutions. The 3P Directory is one such tool.

The Directory categorizes anti-trafficking organizations based on their key activities in three policy dimensions – protection, prosecution and prevention – to shed light on the existing efforts.

The Directory demonstrates where resources are mainly focused and provides intel to better allocate the limited funding in the future. The 3P Directory can foster the sharing of knowledge, the development of best practices and the initiation of partnerships among stakeholders. Those assisting the survivors of human trafficking will be better informed and thus more effective.

The 3P Directory will also help strengthen the 4P policy dimension – partnership.

Design by Bernd Durrwachter

The 3P Directory includes organizations from Allies Database, developed by MA Coalition to End Human Trafficking (MCEHT), mainly focusing on Massachusetts.

Users have the flexibility to filter the directory by the 3P policy dimensions –protection, prosecution and prevention, location, types of trafficking, population served and the key terms by clicking on one of the filter buttons or using the search button. The search button allows for filtering one or more words using a space between the words. For example, if a user wants to see all the organizations located in Boston that focus on children and protection, they can type “Boston children protection” in the search box. For a list of organizations with their main activities focused on prevention, the user can click on the filter button “prevention” or use the search box.

The 3P policy dimensions – protection, prosecution and prevention – are reflected in the Protocol to Prevent, Suppress and Punish Trafficking in Persons, Especially Women and Children (Palermo Protocol or Anti-Trafficking Protocol), the United Nations Convention Against Transnational Organized Crime (UNTOC) and in the United States’ Trafficking Victims Protection Act (TVPA). They are used as the fundamental framework around the world to combat human trafficking. The 3P Directory measures and evaluates the three main policy dimensions based on the requirements of Anti Trafficking Protocol.

Our categorization is an adoption of the 3P Policy Index Cho, Dreher & Neumayer (2014) developed using the US Department of State’s Annual Reports of Trafficking in Persons and UN Office on Drugs and Crime Reports on Trafficking in Persons: Global Patterns. The index measures the three main dimensions of anti-trafficking policies of the governments of up to 180 countries over 2000 – 2010 period based on the requirements of Anti Trafficking Protocol.

If the organization you represent is missing and you would like your organization to be added to the 3P Directory or if you have any other inquiries, please send an email to