Selective Incapacitation and Public Policy: Evaluating California's Imprisonment Crisis

Technical Appendix B

167 Technical Appendix B Example of Simulation Model Code What follows is the code used to simulate the baseline structural model in Berkeley Madonna for one population subgroup. As explained in chapter 7, the code is largely repetitive, with variability in start values and transition parameter estimates for different subpopulations.The following is provided to give the interested reader the opportunity to replicate the functional form of the simulation models presented in this book. METHOD RK4 STARTTIME ⫽ 0 STOPTIME⫽ 31 DT ⫽ 1.0 ARRESTEDwm1(t) ⫽ ARRESTEDwm1(t ⫺ dt) ⫹ (pop2ar_wm1 ⫺ ar2jail_wm1 ⫺ ar2pop_wm1 ⫺ ar2strt_wm1) * dt pop2ar_wm1 ⫽ (NEWARRwm1* incrpop2ar_wm1) INIT ARRESTEDwm1 ⫽ 6452 NEWARRwm1 ⫽ 6452 bail_wm1 ⫽ .599 INIT STREETwm1 ⫽ 3865 drop_rate_wm1 ⫽ .373 detain_rate_wm1 ⫽ .028 acquit_wm1 ⫽ .10 convJL_wm1 ⫽ .05 convSTR_wm1 ⫽ .10 INIT JAILwm1 ⫽665 INIT PROBATIONwm1 ⫽ 4,170 INIT PRISONwm1 ⫽ 70 INIT PAROLEwm1 ⫽ 24 endparole_wm1 ⫽ .85 endpris_wm1 ⫽ .15 endprob_wm1 ⫽ .3470 incrpop2ar_wm1⫽ DELAY (.6, 15, .85) incparo2pris_wm1 ⫽ .15 incpris2paro_wm1 ⫽ .3 incrar2jail_wm1 ⫽ DELAY (1.7, 16, 1.03) incrar2pop_wm1 ⫽ .9 incrar2strt_wm1 ⫽ 1.05 incrjail2pop_wm1 ⫽ 1.05 incrjail2pris_wm1 ⫽ 1 incrjl2prob_wm1 ⫽ 1 incrparo2pop_wm1 ⫽ 1 incrpris2pop_wm1 ⫽ 1 incrprob2jl_wm1 ⫽ .9 incrprob2pop_wm1 ⫽ .9 incrstrt2pris_wm1 ⫽ .5 incrstrt2prob_wm1 ⫽ DELAY (1.3, 14, .89) incstrt2jail_wm1 ⫽ 1 incstrt2pop_wm1 ⫽ 1 jailsentSTR_wm1 ⫽ .07 jrelrate_wm1 ⫽ .40; .05 ⫹ {end sentence} parolrel_wm1 ⫽ .7 probsentS_wm1 ⫽ .19 probviolJL_wm1 ⫽ .30 violparo_wm1 ⫽ .6 violprJL_wm1 ⫽ .3 ar2jail_wm1 ⫽ (ARRESTEDwm1*detain_rate_wm1)*incrar2jail_wm1 ar2pop_wm1 ⫽ (ARRESTEDwm1*drop_rate_wm1)*incrar2pop_wm1 ar2strt_wm1 ⫽ (ARRESTEDwm1*bail_wm1)*incrar2strt_wm1 JAILwm1(t) ⫽ JAILwm1(t ⫺ dt) ⫹ (ar2jail_wm1 ⫹ strt2jail_wm1 ⫹ prob2jl_wm1 ⫺ jail2pop_wm1 ⫺ jail2pris_wm1 ⫺ jl2prob_wm1 ) * dt ar2jail_wm1 ⫽ (ARRESTEDwm1*detain_rate_wm1)*incrar2jail_wm1 168 Technical Appendix B strt2jail_wm1 ⫽ (STREETwm1*jailsentSTR_wm1)*incstrt2jail_wm1 prob2jl_wm1 ⫽ (PROBATIONwm1*probviolJL_wm1)*incrprob2jl_wm1 jail2pop_wm1 ⫽ (JAILwm1*jrelrate_wm1)*incrjail2pop_wm1 jail2pris_wm1 ⫽ (JAILwm1*convJL_wm1)*incrjal2pris_wm1 jl2prob_wm1 ⫽ (PROBATIONwm1*violprJL_wm1)*incrjl2prob_wm1 PAROLEwm1(t) ⫽ PAROLEwm1(t ⫺ dt) ⫹ (pris2paro_wm1 ⫺ paro2pris_wm1 ⫺ paro2pop_wm1) * dt pris2paro_wm1 ⫽ (PRISONwm1*parolrel_wm1)*incpris2paro_wm1 paro2pris_wm1 ⫽ (PAROLEwm1*violparo_wm1)*incparo2pris_wm1 paro2pop_wm1 ⫽ (PAROLEwm1*endparole_wm1)*incrparo2pop_wm1 jail2pop_wm1 ⫽ (JAILwm1*jrelrate_wm1)*incrjail2pop_wm1 ar2pop_wm1 ⫽ (ARRESTEDwm1*drop_rate_wm1)*incrar2pop_wm1 strt2pop_wm1 ⫽ (STREETwm1*acquit_wm1)*incstrt2pop_wm1 pris2pop_wm1 ⫽ (PRISONwm1*endpris_wm1)*incrpris2pop_wm1 prob2pop_wm1 ⫽ (PROBATIONwm1*endprob_wm1)*incrprob2pop_wm1 paro2pop_wm1 ⫽ (PAROLEwm1*endparole_wm1)*incrparo2pop_wm1 pop2ar_wm1 ⫽ (NEWARRwm1)*incrpop2ar_wm1 PRISONwm1(t) ⫽ PRISONwm1(t ⫺ dt) ⫹ (jail2pris_wm1 ⫹ paro2pris_wm1 ⫹ strt2pris_wm1 ⫺ pris2paro_wm1 ⫺ pris2pop_wm1) * dt jail2pris_wm1 ⫽ (JAILwm1*convJL_wm1)*incrjail2pris_wm1 paro2pris_wm1 ⫽ (PAROLEwm1*violparo_wm1)*incparo2pris_wm1 strt2pris_wm1 ⫽ (STREETwm1*convSTR_wm1)*incrstrt2pris_wm1 pris2paro_wm1 ⫽ (PRISONwm1*parolrel_wm1)*incpris2paro_wm1 pris2pop_wm1 ⫽ (PRISONwm1*endpris_wm1)*incrpris2pop_wm1 PROBATIONwm1(t) ⫽ PROBATIONwm1(t ⫺ dt) ⫹ (jl2prob_wm1 ⫹ strt2prob_wm1 ⫺ prob2pop_wm1 ⫺ prob2jl_wm1) * dt jl2prob_wm1 ⫽ (PROBATIONwm1*violprJL_wm1)*incrjl2prob_wm1 strt2prob_wm1 ⫽ (STREETwm1*probsentS_wm1)*incrstrt2prob_wm1 prob2pop_wm1 ⫽ (PROBATIONwm1*endprob_wm1)*incrprob2pop_wm1 prob2jl_wm1 ⫽ (PROBATIONwm1*probviolJL_wm1)*incrprob2jl_wm1 STREETwm1(t) ⫽ STREETwm1(t ⫺ dt) ⫹ (ar2strt_wm1 ⫺ strt2pop_wm1 ⫺ strt2jail_wm1 ⫺ strt2prob_wm1 ⫺ strt2pris_wm1) * dt ar2strt_wm1 ⫽ (ARRESTEDwm1*bail_wm1)*incrar2strt_wm1 strt2pop_wm1 ⫽ (STREETwm1*acquit_wm1)*incstrt2pop_wm1 strt2jail_wm1 ⫽ (STREETwm1*jailsentSTR_wm1)*incstrt2jail_wm1 strt2prob_wm1 ⫽ (STREETwm1*probsentS_wm1)*incrstrt2prob_wm1 strt2pris_wm1 ⫽ (STREETwm1*convSTR_wm1)*incrstrt2pris_wm1 Technical Appendix B 169 ...