2

Table S1

Taxpayer Expenses for Referred Youths per Arrest Category by Therapy Condition

Therapy condition
Multisystemic therapy (MST) / Individual therapy
(IT)
Arrest category / Arrest expense ($) / Arrest distribution (%) / Expected taxpayer expense ($)a / Arrest distribution (%) / Expected taxpayer expense ($)a
Murder/ manslaughter / 307,519 / 0.00 / 0 / 0.00 / 0
Sexual / 78,458 / 0.68 / 536 / 0.82 / 641
Robbery / 80,826 / 0.34 / 274 / 0.27 / 219
Assault / 49,183 / 1.71 / 839 / 4.63 / 2,278
Property / 9,438 / 33.11 / 3,125 / 25.34 / 2,392
Drug / 13,927 / 8.53 / 1,188 / 11.17 / 1,556
Theft/larceny / 1,465 / 11.60 / 170 / 16.08 / 236
Stolen property / 3,482 / 1.02 / 36 / 2.18 / 76
Fraud / 3,336 / 7.17 / 239 / 4.63 / 155
Misdemeanor assault / 2,287 / 12.63 / 289 / 16.62 / 380
Misdemeanor drug / 3,759 / 23.21 / 872 / 18.26 / 686
Total / 100.00 / 7,568 / 100.00 / 8,619

Note. All expenses are expressed in 2012 dollars. Sample sizes for therapy conditions are MST (n = 92) and IT (n = 84).

aProduct of arrest expense/loss and arrest distribution for therapy condition.
Table S2

Crime Victim Tangible and Intangible Expenses Avoided for Multisystemic Therapy

per Referred Youth

Arrest category / Arrest expense ($) / Distribution of expected offenses (%)a / Avoided expense/loss ($)b
Murder/ manslaughter
Tangible
Intangible / 900,117
1,670,239 / 0.01
0.01 / 6,571
12,193
Sexual
Tangible
Intangible / 5,447
72,188 / 0.07
0.07 / 278
3,689
Robbery
Tangible
Intangible / 2,059
5,096 / 0.41
0.41 / 616
1,525
Assault
Tangible
Intangible / 1,277
6,936 / 0.62
0.62 / 578
3,139
Property
Tangible
Intangible / 493
0 / 11.66
11.66 / 4,199
0
Drug
Tangible
Intangible / 0
0 / 87.23
87.23 / 0
0
Total
Tangible
Intangible /
/ 100.00
100.00 / 12,242
20,546

Note. All expenses are expressed in 2012 dollars.

aFrom Aos et al. (2001). bProduct of lambda (168.91), expected change in felony offenses (0.43), arrest expense/loss, and distribution of expected offenses.


Table S3

Cumulative Benefit of Multisystemic Therapy per Referred Youth Based on Maximum and Minimum Plausible Values of Model Parameters

Maximum plausible value / Minimum plausible value
Model parameter / Net present value ($)a / Benefit–cost ratiob / Net present value ($)a / Benefit–cost ratiob
Crime victim intangible benefits / 52,882 / 6.62 / 20,131 / 3.14
Discount ratesc / 26,676 / 3.84 / 40,926 / 5.35

Note. All expenses are expressed in 2012 dollars.

aThe difference between the cumulative benefit and the incremental cost of providing multisystemic therapy (MST) over individual therapy (IT; i.e., $9,405). bThe cumulative benefit divided by the incremental cost of providing MST over IT. cHigher values for discount rates are associated with lower future benefits and, thus, with smaller net present values and benefit–cost ratios.


Table S4

Taxpayer Expenses for Siblings per Arrest Category by Therapy Condition

Therapy condition
Multisystemic therapy (MST) / Individual therapy
(IT)
Arrest category / Arrest expense ($) / Arrest distribution (%) / Expected taxpayer expense ($)a / Arrest distribution (%) / Expected taxpayer expense ($)a
Murder/ manslaughter / 307,519 / 0.00 / 0 / 0.00 / 0
Sexual / 78,458 / 4.62 / 3,621 / 1.39 / 1,090
Robbery / 80,826 / 0.00 / 0 / 1.39 / 1,115
Assault / 49,183 / 7.69 / 3,783 / 1.39 / 683
Property / 9,438 / 16.92 / 1,597 / 16.67 / 1,573
Drug / 13,927 / 4.62 / 643 / 12.50 / 1,740
Theft/larceny / 1,465 / 6.15 / 90 / 11.11 / 163
Stolen property / 3,482 / 0.00 / 0 / 0.00 / 0
Fraud / 3,336 / 18.46 / 616 / 25.00 / 834
Misdemeanor assault / 2,287 / 10.77 / 246 / 8.33 / 191
Misdemeanor drug / 3,759 / 30.77 / 1,156 / 22.22 / 835
Total / 100.00 / 11,752 / 100.00 / 8,224

Note. All expenses are expressed in 2012 dollars. Sample sizes for therapy conditions are MST (n = 60) and IT (n = 50).

aProduct of arrest expense/loss and arrest distribution for therapy condition.


Table S5

Crime Victim Tangible and Intangible Expenses Avoided for Multisystemic Therapy

per Sibling

Arrest category / Arrest expense ($) / Distribution of expected offenses (%)a / Avoided expense/loss ($)b
Murder/ manslaughter
Tangible
Intangible / 900,117
1,670,239 / 0.01
0.01 / 1,723
3,197
Sexual
Tangible
Intangible / 5,447
72,188 / 0.07
0.07 / 73
967
Robbery
Tangible
Intangible / 2,059
5,096 / 0.41
0.41 / 162
400
Assault
Tangible
Intangible / 1,277
6,936 / 0.62
0.62 / 152
823
Property
Tangible
Intangible / 493
0 / 11.66
11.66 / 1,101
0
Drug
Tangible
Intangible / 0
0 / 87.23
87.23 / 0
0
Total
Tangible
Intangible /
/ 100.00
100.00 / 3,211
5,387

Note. All expenses are expressed in 2012 dollars.

aFrom Aos et al. (2001). bProduct of lambda (168.91), expected change in felony offenses (0.11), arrest expense/loss, and distribution of expected offenses.


Table S6

Cumulative Benefit of Multisystemic Therapy per Sibling Based on Maximum and Minimum Plausible Values of Model Parameters

Maximum plausible value / Minimum plausible value
Model parameter / Net present value ($)a / Benefit–cost ratiob / Net present value ($)a / Benefit–cost ratiob
Crime victim intangible benefits / 12,334 / — / 3,746 / —
Sibling juvenile arrest ratesc / 7,277 / — / — / —
Discount ratesd / 6,251 / — / 8,726 / —

Note. All expenses are expressed in 2012 dollars. Because there is no incremental cost for sibling treatment effects, the incremental cost of multisystemic therapy (MST) over individual therapy (IT) was set to $0 for all calculations. Dashes indicate that values were not calculated.

aThe difference between the cumulative benefit and the incremental cost of providing MST over IT (i.e., $0). bThe cumulative benefit divided by the incremental cost of providing MST over IT. cA minimum plausible value was not calculated because the rate used to derive cumulative benefits (i.e., zero arrests) already represented the lowest possible value. dHigher values for discount rates are associated with lower future benefits and, thus, with smaller net present values and benefit–cost ratios.