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Washington State Institute for Public Policy
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Police diversion (pre-arrest and pre-booking)

Adult Criminal Justice
Benefit-cost methods last updated December 2024.  Literature review updated September 2024.
Police diversion programs redirect individuals who are at risk of arrest (pre-arrest) or have been arrested (pre-booking) away from the criminal legal system. These types of diversion programs are typically focused on people engaging in drug-related or low-level offenses. Eligible individuals receive case management and connection to services in lieu of processing through the criminal legal system. Services include substance use treatment, mental health counseling, housing assistance, and long-term wraparound services tailored to each individual. Police diversion programs typically do not have a fixed duration; they provide services and case management as long as needed.
 
ALL
BENEFIT-COST
META-ANALYSIS
CITATIONS
For an overview of WSIPP's Benefit-Cost Model, please see this guide. The estimates shown are present value, life cycle benefits and costs. All dollars are expressed in the base year chosen for this analysis (2023).  The chance the benefits exceed the costs are derived from a Monte Carlo risk analysis. The details on this, as well as the economic discount rates and other relevant parameters are described in our Technical Documentation.
Benefit-Cost Summary Statistics Per Participant
Benefits to:
Taxpayers $7,376 Benefits minus costs $19,469
Participants $0 Benefit to cost ratio $7.39
Others $12,973 Chance the program will produce
Indirect $2,165 benefits greater than the costs 100%
Total benefits $22,514
Net program cost ($3,045)
Benefits minus cost $19,469

Meta-analysis is a statistical method to combine the results from separate studies on a program, policy, or topic to estimate its effect on an outcome. WSIPP systematically evaluates all credible evaluations we can locate on each topic. The outcomes measured are the program impacts measured in the research literature (for example, impacts on crime or educational attainment). Treatment N represents the total number of individuals or units in the treatment group across the included studies.

An effect size (ES) is a standard metric that summarizes the degree to which a program or policy affects a measured outcome. If the effect size is positive, the outcome increases. If the effect size is negative, the outcome decreases. See Estimating Program Effects Using Effect Sizes for additional information on how we estimate effect sizes.

The effect size may be adjusted from the unadjusted effect size estimated in the meta-analysis. Historically, WSIPP adjusted effect sizes to some programs based on the methodological characteristics of the study. For programs reviewed in 2024 or later, we do not make additional adjustments, and we use the unadjusted effect size whenever we run a benefit-cost analysis.

Research shows the magnitude of effects may change over time. For those effect sizes, we estimate outcome-based adjustments, which we apply between the first time ES is estimated and the second time ES is estimated. More details about these adjustments can be found in our Technical Documentation.

Meta-Analysis of Program Effects
Outcomes measured Treatment age No. of effect sizes Treatment N Effect sizes (ES) and standard errors (SE) used in the benefit-cost analysis Unadjusted effect size (random effects model)
First time ES is estimated Second time ES is estimated
ES SE Age ES SE Age ES p-value
Crime
Involvement in the criminal justice system (e.g., arrests, charges, convictions, incarceration) measured through administrative records (e.g. court records, arrests) or self-report.
 39 6 908 -0.421 0.118 40 -0.421 0.118 48 -0.421 0.001
1In addition to the outcomes measured in the meta-analysis table, WSIPP measures benefits and costs estimated from other outcomes associated with those reported in the evaluation literature. For example, empirical research demonstrates that high school graduation leads to reduced crime. These associated measures provide a more complete picture of the detailed costs and benefits of the program.

2“Others” includes benefits to people other than taxpayers and participants. Depending on the program, it could include reductions in crime victimization, the economic benefits from a more educated workforce, and the benefits from employer-paid health insurance.

3“Indirect benefits” includes estimates of the net changes in the value of a statistical life and net changes in the deadweight costs of taxation.
Detailed Monetary Benefit Estimates Per Participant
Affected outcome: Resulting benefits:1 Benefits accrue to:
Taxpayers Participants Others2 Indirect3 Total
Crime Criminal justice system $7,376 $0 $12,973 $3,688 $24,037
Program cost Adjustment for deadweight cost of program $0 $0 $0 ($1,523) ($1,523)
Totals $7,376 $0 $12,973 $2,165 $22,514
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Detailed Annual Cost Estimates Per Participant
Annual cost Year dollars Summary
Program costs $3,124 2024 Present value of net program costs (in 2023 dollars) ($3,045)
Comparison costs $0 2024 Cost range (+ or -) 30%
Program costs include all costs associated with program staff, administration, and services provided to participants. Costs were determined using the total budget for Washington's Recovery Navigator Program (RNP) in state fiscal year 2024. Per person program costs were calculated using the Health Care Authority's estimate of unique RNP clients in state fiscal year 2024.
The figures shown are estimates of the costs to implement programs in Washington. The comparison group costs reflect either no treatment or treatment as usual, depending on how effect sizes were calculated in the meta-analysis. The cost range reported above reflects potential variation or uncertainty in the cost estimate; more detail can be found in our Technical Documentation.
Benefits Minus Costs
Benefits by Perspective
Taxpayer Benefits by Source of Value
Benefits Minus Costs Over Time (Cumulative Discounted Dollars)
The graph above illustrates the estimated cumulative net benefits per-participant for the first fifty years beyond the initial investment in the program. We present these cash flows in discounted dollars. If the dollars are negative (bars below $0 line), the cumulative benefits do not outweigh the cost of the program up to that point in time. The program breaks even when the dollars reach $0. At this point, the total benefits to participants, taxpayers, and others, are equal to the cost of the program. If the dollars are above $0, the benefits of the program exceed the initial investment.

Citations Used in the Meta-Analysis

Nyland, J.E., Zhang, A., Balles, J.A., Nguyen, T.H., White, V., Albert, L.A., Henningfield, M. F., & Zgierska, A.E. (2024). Law enforcement-led, pre-arrest diversion-to-treatment may reduce crime recidivism, incarceration, and overdose deaths: Program evaluation outcomes. Journal of Substance Use & Addiction Treatment, 165.

Arora, A., & Bencsik, P. (2023). Policing substance use: Chicago’s treatment program for narcotics arrests (SSRN Scholarly Paper 4599291). Social Science Research Network.

Malm, A., Perrone, D., & Magana, E. (2020). Law Enforcement Assisted Diversion (LEAD) external evaluation report to the California State Legislature. California State University Long Beach.

Gilbert, A.R., Siegel, R., Easter, M.M., Sivaraman, J.C., Hofer, M., Ariturk, D., Swartz, M.S., & Swanson, J. W. (2023). Law Enforcement Assisted Diversion (LEAD): A multi-site evaluation of North Carolina LEAD programs. Duke University School of Medicine.

Dole, J., & Freeman, L. (2018). Evaluation of Santa Fe’s LEAD Program: Criminal justice outcomes. New Mexico Sentencing Commission.

Collins, S.E., Lonczak, H.S., Clifasefi, S.L. (2019). Seattle's law enforcement assisted diversion (LEAD): Program effects on criminal justice and legal system utilization and costs. Journal of Experimental Criminology, 1-11.