Download presentation
Presentation is loading. Please wait.
Published byDouglas Jones Modified over 8 years ago
1
Benefits & Costs A Workshop on “Big-Picture” Considerations if You Want to Compute Benefit-Cost Estimates Canadian Congress on Criminal Justice Vancouver, British Columbia October 4, 2013 Steve Aos Director Washington State Institute for Public Policy Phone: (360) 586-2740 E-mail: saos@wsipp.wa.gov Institute Publications: www.wsipp.wa.gov 1 of 9
2
The Goal design a benefit-cost framework that produces: Consistent, policy-relevant, investment information for a wide array of public policy topics. 2 of 9 Versatile, QuickConsistent
3
In concept, things are simple! Example: $3,000 investment; $500 /yr return; 20 years; 3% discount rate Net Present Value $4,526.12 Cell D26 =NPV(A2,D4:D23) or B24 – C24 Benefit/Cost Ratio $2.55 Cell D25 =B24/C24 Return on Investment 19.30% Cell D27 =IRR(D4:D23) Summary Statistics PV of Benefits & Costs $7,438.74 Cell B24 = NPV(A2,B4:B23) $2,912.62 Cell C24 = NPV(A2,C4:C23) Q x P Background I: Benefits, Costs, and Time 3 of 9
4
The Basic Benefit-Cost Computational Engine (Q X P) - C = NV Q= The quantity of something of interest to you. P= The unit price of that quantity. What is the Q worth to you?) C= The cost of supplying the Q (quantity). NV= The Net Value (profit or loss) to you. Some Other Useful Definitions Benefits= Q X P Costs= C Benefit-Cost Ratio= (Q X P) / C “Cost Effectiveness” Ratio= Q / C Break-Even Success Rate= C/P Net Present Valuenext slide Background II. 4 of 9
5
(Q X P ) - C (1+D) t = N V t = 1 N The Basic Benefit-Cost Computational Engine t= Some time period (most often, a year). N= Some number of time periods in the future. D= A “Discount” rate. NPV= Net Present Value. ttt To calculate a NET PRESENT VALUE, we are going to add a few items that deal with resource flows over time. P Background III. 5 of 9
6
The Basic Benefit-Cost Computational Engine For Use with Program Evaluations (( %WOT - %WT ) X P ) - C = NPV ( Q X P ) - C = NPV %WOT: The outcome for those without treatment %WOT: The outcome for those with treatment 6 of 9
7
The Basic Benefit-Cost Computational Engine (( %WOT - %WT ) X P ) - C = NPV 7 of 9 Fictional Family Therapy (FFT) NPV= The Net Present Value of FFT. B/C Ratio=The Benefit-to-Cost Ratio of FFT. $3000= C: The cost to treat one youth with FFT. 50%= %WOT: The percentage of youth without treatment, FFT, that continues to engage in criminality. 45%= %WT: The percentage of youth with treatment, FFT, that continues to engage in criminality. $150,000= P: The price we pay if the youth continues to engage in criminal behavior (in present-value terms). NPV = ((.50 -.45 ) X $150,000) - $3,000 = $4,500 B/C Ratio = ((.50 -.45 ) X $150,000) / $3,000 = $2.50 This is the fundamental, cause-and-effect, program evaluation question. Benefit-cost analysis does not solve this matter! This can be a green eyeshade exercise. Characteristics of relevant untreated populations This is the fundamental, cause-and-effect, program evaluation question. Benefit-cost analysis does not solve this matter! This is a big deal. It can be done in a “top down” or “bottom up” manner. For crime, need to know about the victim costs of crime, the criminal justice system costs of responding to crime, and populations served.
8
You Also Need to Measure Risk ( %WOT - %WT ) X P ) - C = NPV 8 of 9 Fictional Family Therapy $3000 ( 10%)= C 50%= %WOT 45% (.025 se) = %WT $150,000 ( 20%) = P NPV, mean = (.50 -.45 ) X $150,000) - $3,000 = $4,500 Monte Carlo Simulation Run the model 10,000 times Risk: Probability that NPV is Less than Zero = 6.8%
9
9 of 9 Evidence-Based Lists Can Now be Produced: What Works, and What Pays Off? “Consumer Reports” Lists: What Works? What Doesn’t? What Can Give Washington Taxpayers a Good Return on Their Money? Given the Current Level of Rigorous Research, What Don’t We Know?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.