inctax-module.sas

/* PTM+v2 model */ 
/* inctax.sas module */ 
/* objective: calculate income tax liabilities */ 
/* define various output variable arrays */ 
/* note: variables contained in each array are listed in macro variables  appearing in array definitions */ 
/* e.g. the tivars macro variable appearing in first array definition may  list variables ti_ST ti_NS and ti_DV */ 
/* these macro variable lists are created in the macvars module according  to tax parameters specified by user */ 
/* i.e. they will depend on the number of streams and tax bands, and their  names, as set in the tax parameters */ 
array tis(&PTAX_NSTREAMS.) &tivars.; /*  total income by income stream */ 
array ads(&PTAX_NSTREAMS.) &advars.; /*  allowances & deductions allocated by income stream */ 
array taxincs(&PTAX_NSTREAMS.) &taxincvars.; /* total  income after allowances & deductions by income stream */ 
array taxlim(&PTAX_NBANDS.); /*  width of each tax band */ 
array allow(&PTAX_NSTREAMS.) &allowvars.; /*  stream-specific allowances due by income stream */ 
/* (e.g. allow(2) would be savings allowance due */ 
array taxinc1(&PTAX_NSTREAMS.,&PTAX_NBANDS.) &incvars1.; /* 2D array:  taxable income before stream allowances by (income stream,tax band) */ array taxinc2(&PTAX_NSTREAMS.,&PTAX_NBANDS.) &incvars2.; /* 2D array:  taxable income after stream allowances by (income stream,tax band) */ 
array taxrate(&PTAX_NSTREAMS.,&PTAX_NBANDS.) &ratevars.; /* 2D array:  tax rates by (income stream,tax band) */ 
array taxpre(&PTAX_NSTREAMS.,&PTAX_NBANDS.) &taxprevars.; /* 2D array:  liabilities before tax credits by (income stream,tax band) */ 
array tax(&PTAX_NSTREAMS.,&PTAX_NBANDS.) &taxvars.; /* 2D  array: liabilities after tax credits by (income stream,tax band) */ 
array taxb(&PTAX_NBANDS.) &taxvarsb.; /*  liabilities after tax credits by tax band */ 
array tptax(&PTAX_NBANDS.) &tptaxvars.; /*  taxpayers' TOTAL liability recorded against the tax band corresponding to  their highest marginal rate */ 
/* e.g. if tax band 3 is the HR band, then tptax(3) would  hold total liabilities of HR taxpayers */ 
array penchrate(&PTAX_NBANDS.); 
/* pensions charge tax rates */
OFFICIAL 
/* note: not bothering to name the elements in this array  as these variables will not be kept */ 
/* compute tax at last record for each individual */ 
if last.sref then do; 
/* initialise flags for cases within aged, MCA and univeral tapers */ 
agetaper = 0; 
mcataper = 0; 
pataper = 0; 
/* initialise total income */ 
ti = 0; 
/* assign elements in the ti by income stream array; and sum total  income */ 
/* note: this code is written in macro format so that %do ... %end  macro language can be used (it is not valid outside a macro)  the %do ... %end formulation creates a looping macro variable  &i. which can then be used in the RHS double  
resolution that assigns the income streams */ 
/* this macro formulation is ONLY required for assignments of this  type */ 
%macro assign(); 
%do i = 1 %to &PTAX_NSTREAMS.; 
tis(&i.) = &&PTAX_STREAMDEF&i.; /* double  
resolves to each income stream definition as step through loop */ /*  
e.g. when macro variable i = 1, RHS first resolves to &PTAX_STREAMDEF1 
which subsequently resolves to its value determined by the  corresponding parameter value */ 
ti = sum(ti,tis(&i.)); 
%end; 
%mend assign; 
%assign; 
/* create some income variables of interest */ 
/* note: output variables only - not used in tax calculations */ ppp = tis(1) - INCPROP; /* NSND excluding net  income from property */ 
pdi = tis(2) + tis(3) + INCPROP; /* Investment (savings/dividends)  income including net income from property */ 
/* note: this code clearly assumes that NSND, savings and dividends  are income streams 1, 2 & 3 respectively */ 
/* total deductions */ 
deds = sum(EMP_SCH_, RAR, STK_RELI, SUPANN, COVNTS, GIFTAID,  GIFTPROP, GIFT_INV, MOTHDEDS, DEFICIEN); 
/* income after deductions */ 
iad = max(0,ti-deds);
OFFICIAL 
/* assign PAs */ 
pas = 0; 
if TAGE < &PTAX_AGED. then pas = &PTAX_PA.; /* normal  PA*/ 
else if TAGE < &PTAX_SAGED. then pas = &PTAX_APA.; /* aged  PA */ 
else pas = &PTAX_SAPA.; 
/* higher aged PA */ 
/* age-related taper */ 
if pas > &PTAX_PA. then do; 
pas0 = pas; 
if iad >= &PTAX_AILT. then pas = max(&PTAX_PA.,ceil(pas-((iad- &PTAX_AILT.)*&PTAX_AILTR.))); /* use ceil to match PTM model */ if pas0 > pas > &PTAX_PA. then agetaper = 1; /* flag  cases within aged taper */ 
end; 
/* assign MCA */ 
/* do it here before variable pas affected by universal PA taper */ 
/* note: input variable MCAPERC shows proportion of MCA due based on  proportion of year married,  
but is not a true proportion; has been scaled by factor 1000  for formatting purposes */ 
mcas = 0; 
if MCAPERC > 0 and MAXAGE > =&PTAX_MCA_MA. then do; 
/* males (note: MCA taper applies only to males) */ 
if SEX = 1 then do; 
/* compute pas_taper such that PTAX_AILT. + pas_taper  
= taper start point for MCA */ 
pas_taper = 0; 
if (TAGE >= &PTAX_AGED. and TAGE < &PTAX_SAGED.) then  
pas_taper = (&PTAX_APA.-pas)/&PTAX_AILTR.; 
else if TAGE >= &PTAX_SAGED. then pas_taper =  
(&PTAX_SAPA.-pas)/&PTAX_AILTR.; 
/* apply taper as required */ 
if MAXAGE >= &PTAX_SAGED. and SEX = 1 then do; 
if iad >= &PTAX_AILT. + pas_taper then 
mcasdue =  
max(&PTAX_MMCA.,&PTAX_MCA_75.-(iad-&PTAX_AILT.-pas_taper)*&PTAX_MCATR.) *  (MCAPERC/10000); 
else mcasdue = &PTAX_MCA_75. * (MCAPERC/10000); 
if 0 < mcasdue < &PTAX_MCA_75. * (MCAPERC/10000)  
then mcataper = 1; /* flag cases within MCA taper */ 
end; 
else if (MAXAGE >= &PTAX_AGED. and MAXAGE < &PTAX_SAGED.)  and SEX = 1 then do; 
if iad >= &PTAX_AILT. + pas_taper then 
OFFICIAL 
mcasdue =  
max(&PTAX_MMCA.,&PTAX_MCA_65.-(iad-&PTAX_AILT.-pas_taper)*&PTAX_MCATR.) *  (MCAPERC/10000); 
else mcasdue =&PTAX_MCA_65. * (MCAPERC/10000); 
if 0 < mcasdue < &PTAX_MCA_65. * (MCAPERC/10000)  
then mcataper = 1; /* flag cases within MCA taper */ end; 
if MCATYPE = 0 then mcas = round(mcasdue,0.01); 
/* No transfer */ 
 else if MCATYPE = 2 then mcas = round(max(0,mcasdue- (&PTAX_MMCA./2)),0.01); /* Half transfer */ 
 else if MCATYPE = 1 then mcas = round(max(0,mcasdue- &PTAX_MMCA.),0.01); /* Full transfer */ 
if mcas = 0 then mcataper = 0; 
end; /* sex = 1 */ 
/* females */ 
else if SEX = 2 and MAXAGE >=&PTAX_SAGED. then mcas =  
round(&PTAX_MCA_75.*(MCAPERC/10000),0.01); 
else if SEX = 2 and MAXAGE >=&PTAX_AGED. then mcas =  
round(&PTAX_MCA_65.*(MCAPERC/10000),0.01); 
end; /* MCAPERC > 0 and MAXAGE > =&PTAX_MCA_MA. */ 
/* assign BPA using BPAPERC (note: like MCAPERC this is scaled up by  factor 1000 on input dataset) */ 
if bpaperc > 0 then bpadue = round(&PTAX_BPA.*(BPAPERC/10000),1); else bpadue = 0; 
/* PA universal "£100k" taper */ 
pas0 = pas; 
if iad >= &PTAX_PAT. then pas = max(0,pas-int((iad- 
&PTAX_PAT.)*&PTAX_PATR.)); 
if pas0 > pas > 0 then pataper = 1; /* flag cases within PA taper */ 
/* remove allowances for non-residents */ 
if NR_NOPA = "Y" then do;  
pas = 0; 
mcas = 0;  
bpadue = 0; 
agetaper = 0; 
pataper = 0; 
mcataper = 0;  
end; 
/* marriage allowance (transferrable tax allowance) */ 
/* code assumes that age of both individuals in couple is the same  (i.e. so get same PA) */ 
tta = 0;
OFFICIAL 
/* derive HR limit - determines who can receive a PA transfer and can  differ for Scottish taxpayers */ 
if gor_code ne 'S99999999' then brlimit = &&PTAX_LIM&PTAX_BRLIM.; else if gor_code = 'S99999999' then brlimit =  
&&PTAX_LIM&PTAX_BRLIM_S.; 
/* Bringing this inctax module forward will mean matched data is  automatically checked for eligibility before inclusion, even in future base  years. */ 
/* Total number of cases with an increased tta will be the same (or  similar, due to randomness) because we are still imputing to hit the same  target. */ 
/* There will simply be a slight increase in the number of imputed  cases. */ 
/* initialise variables needed for marriage allowance */ 
ma_inc_cond_receive = 0; 
ma_inc_cond_give = 0; 
ma_flag = 0; 
matched_eligible = 0; 
/* set criteria for receiving PA, store as binary variable */ if iad-sum(pas,bpadue)<=brlimit then do; 
if (TAGE<&PTAX_AGED. and PARTNER_IAD<=&PTAX_PA.)  
or (TAGE>=&PTAX_AGED. and TAGE<&PTAX_SAGED. and  
PARTNER_IAD<=&PTAX_APA.)  
or (TAGE>=&PTAX_SAGED. and  
PARTNER_IAD<=&PTAX_SAPA.) 
then do; 
ma_inc_cond_receive = 1; 
end; 
end; 
/* set criteria for giving PA, store as binary variable */ 
if iad<=max(&PTAX_PA.,pas) and PARTNER_IAD<=&PTAX_PA.+brlimit then  do; 
if (TAGE<&PTAX_AGED. and PARTNER_IAD>&PTAX_PA.)  
or (TAGE>=&PTAX_AGED. and TAGE<&PTAX_SAGED. and  
PARTNER_IAD>&PTAX_APA.)  
or (TAGE>=&PTAX_SAGED. and PARTNER_IAD>&PTAX_SAPA.) 
then do; 
ma_inc_cond_give = 1; 
end; 
end; 
/* high earner recieving PA transfer */ 
/* check if flag exists and the case meets criteria. If so, increase  TTA by the transferrable portion of PA */ 
if iad-sum(pas,bpadue)<=brlimit and m_2018=1 and &TAKEUP_TTA > 0 then  do;
OFFICIAL 
/* amount transferred = normal PA * transferrable  
proportion */ 
tta=ceil((&PTAX_PA.*&PTAX_TTA_PAPROP.)/10)*10; /*  
multiplied and divided by 10 to ensure that tta rounds to nearest 10 */ pas=pas+tta; 
ma_flag = 1; 
matched_eligible=1; 
end; 
/* low earner transferring PA */ 
if iad<=max(&PTAX_PA.,pas) and m_2018 = 0 and n_2018=1 and  &TAKEUP_TTA > 0 then do; 
tta=floor((&PTAX_PA.*-&PTAX_TTA_PAPROP.)/10)*10; /*  
multiplied and divided by 10 to ensure that tta rounds to nearest 10 */ pas=max(0,pas+tta); 
ma_flag = 2; 
matched_eligible = 2; 
end; 
/* now impute to those left who are eligible who did not have the  flag */ 
/* */ 
if ma_inc_cond_receive = 1 and m_2018 = 0 and  
TTA_MARRIED_HIGH_EARNER=1 and ranuni(2222)<=&TAKEUP_TTA. then do; 
/* amount transferred = normal PA * transferrable  
proportion */ 
tta=ceil((&PTAX_PA.*&PTAX_TTA_PAPROP.)/10)*10; /*  
multiplied and divided by 10 to ensure that tta rounds to nearest 10 */ pas=pas+tta; 
ma_flag = 1; 
end; 
if ma_inc_cond_give = 1 and n_2018 = 0 and TTA_MARRIED_LOW_EARNER=1 and ranuni(2222)<=&TAKEUP_TTA. then do; 
tta=floor((&PTAX_PA.*-&PTAX_TTA_PAPROP.)/10)*10; /*  
multiplied and divided by 10 to ensure that tta rounds to nearest 10 */ pas=max(0,pas+tta); 
ma_flag = 2; 
end; 
/* total allowances due at marginal rate ('full') relief */ hpasfull = sum(pas,bpadue); 
/* total allowances and deductions */ 
tot_ad = sum(hpasfull,deds); 
/* taxable income */ 
taxinc = max(0,ti-tot_ad); 
/* assign elements in the allowances/deductions and taxable income by  income stream arrays */ 
/* initialise temporary variable to keep track of  
allowances/deductions remaining */
OFFICIAL 
/* note: this loop can be written in standard code as standard loop  counter i works, macro variable &i. not needed */ 
tempad = tot_ad; 
do i = 1 to &PTAX_NSTREAMS.; 
ads(i) = min(tis(i),tempad); 
tempad = tempad - ads(i); 
taxincs(i) = tis(i) - ads(i); 
end; 
/* assign elements in the taxlim by tax band array */ 
/* note: this array is initialised with the 'width' of each tax band,  i.e. upper limit of band minus  
the upper limit of the previous band (according to parameter  values); but it is later amended during  
tax calculations to show width of each band remaining after  incomes have been allocated from bottom up */ 
%macro assign(); 
/* temporary variable to record upper limit of previous tax  band, initialise at zero */ 
previous = 0; 
%do i = 1 %to &PTAX_NBANDS.; 
/* note: double resolution of macro variable needed in  
assignment below, so this code written in macro format */ 
lim = &&PTAX_LIM&i.; 
taxlim(&i.) = lim - previous; /* gives effective width of  each tax band */ 
previous = lim; 
%end; 
%mend assign; 
%assign; 
/* assign elements in 2D arrays for taxable income, by (income  stream,tax band) */ 
/* note: computing taxable income before stream specific allowances  (e.g. savings and dividends allowances) */ 
/* initialise marginal rate indicator (needed below to assign correct  stream specific allowances */ 
taxtype = 0; 
/* step through income streams in 'stack' order */ 
do s = 1 to &PTAX_NSTREAMS.; 
/* set income equal to taxable income for this stream */ 
tempinc = taxincs(s); 
/* for each stream, step through tax bands */ 
do b = 1 to &PTAX_NBANDS.; 
/* assign taxable income (before stream allowances) for  
this (stream,band) */ 
taxinc1(s,b) = min(tempinc,taxlim(b)); 
/* update marginal rate indicator */ 
if taxinc1(s,b) > 0 and b > taxtype then taxtype = b; 
tempinc = tempinc - taxinc1(s,b); /* update  
income remaining for this stream */ 
taxlim(b) = taxlim(b) - taxinc1(s,b); /* update width  of band remaining */ 
end;
OFFICIAL 
end; 
/* assign stream specific allowances to taxable income for each  stream from bottom tax band upwards */ 
/* then compute tax before tax credits */ 
/* tax credits means all tax reducers granted at fixed relief rate  and computed later (e.g. MCA) */ 
/* however, we do take account of dividends tax credit in  calculations of tax before tax credits below */ 
/* this prevents tax credits later being allocated against dividends  tax liabilities that are covered by  
dividends tax credit when this is not zero */ 
tottaxpre = 0; 
%macro assign(); 
/* step through income streams in 'stack' order */ 
%do s = 1 %to &PTAX_NSTREAMS.; 
/* assign stream allowance due according to taxpayer  
marginal rate */ 
allow(&s.) = 0; 
%do b = 1 %to &PTAX_NBANDS.; 
/* note: double resolution of macro variable needed  
in assignment below (and later), 
so this code written in macro format */ 
if &b. <= taxtype then allow(&s.) =  
&&PTAX_ALLOW_S&s._B&b.; 
%end; 
/* create temporary variable to keep track of stream  
allowance due during allocation to tax bands */ 
tempallow = allow(&s.); 
%do b = 1 %to &PTAX_NBANDS.; 
/* calculate tax rate applicable to this  
(stream,band) */ 
if gor_code NE 'S99999999' and gor_code NE  
'W99999999' then taxrate(&s.,&b.) = &&PTAX_RATE_S&s._B&b.; /* applicable  tax rate rUK */ 
if gor_code = 'S99999999' then taxrate(&s.,&b.) =  
&&PTAX_RATE_S&s._B&b._S; /* applicable tax rate  Scotland only - note this can be chaged to use the flag once in the  dataset*/ 
if gor_code = 'W99999999' then taxrate(&s.,&b.) =  
&&PTAX_RATE_S&s._B&b._W; /* applicable tax rate  Wales only - note this can be chaged to use the flag once in the dataset */ /* if stream = dividends stream use after dividend  
TC rate */ 
if &s. = &PTAX_DIVSTREAM. then taxrate(&s.,&b.) =  
max(0,taxrate(&s.,&b.)- &PTAX_DTCR.); 
/* only allocate stream allowance due to this band  
if a tax liability would arise */ 
/* e.g. prevents savings allowance being allocated  
to LR band if LR savings tax rate is zero */ 
if taxrate(&s.,&b.) > 0 then allowused =  
min(tempallow,taxinc1(&s.,&b.)); 
else allowused = 0; 
/* assign taxable income (after stream allowances)  
for this (stream,band) */
OFFICIAL 
taxinc2(&s.,&b.) = taxinc1(&s.,&b.) - allowused;  
tempallow = tempallow - allowused; 
/* update stream allowance remaining */ 
taxpre(&s.,&b.) =  
taxinc2(&s.,&b.)*taxrate(&s.,&b.); /* assign tax (before tax credits) for  this (stream,band) */ 
taxpres(&s.) =  
round(sum(taxpres(&s.),taxpre(&s.,&b.)),0.01); /* assign tax (before tax  credits) for this (stream only) - new for NSND tax credit */ tottaxpre = sum(tottaxpre,taxpre(&s.,&b.)); 
/* update total tax */ 
%end; 
%end; 
%mend assign; 
%assign; 
/*LLIR_resttricted calc */ 
/*For 18-19 SPI, 50% of LLIR is now given at 20% tax credit. */ /*Modify below to reflect split in policy */ 
/*LLIR_AMT_c = LLIR_AMT_50c; 
LLIR_RES_AMT_TOT_0c=0; 
LLIR_RES_AMT_TOT_50c=  
max(0,LLIR_RES_AMT_50_1+LLIR_RES_AMT_50_2+LLIR_RES_AMT_50_3+LLIR_RES_AMT_50 _4+LLIR_RES_AMT_50_5+LLIR_RES_AMT_50_6+LLIR_RES_AMT_50_7); LLIR_RES_AMT_TOT = LLIR_RES_AMT_TOT_50c;*/ 
/* The above is only needed in the SPI base year, is calculated in step 2,  stage 4 of the IPS process for projections*/ 
LLIR_RESTRICT_INC=FLOOR(MAX(0,TI_ST-PAS-GIFTPROP-GIFT_INV-MOTHDEDS)); LLIR_RESTRICT_AMT_TOT=CEIL(MIN(LLIR_RESTRICT_INC,LLIR_RES_AMT_TOT)); 
/* tax relief value of tax credits/reducers */ 
taxcr =  
sum(MCAS*&PTAX_MCAR.,CITR_TOT*&PTAX_CITR.,ALMY_NEW*&PTAX_ALMY.,VENT_CAP*&PT AX_VENT.,EIS_REL_*&PTAX_EIS.,SEED_EIS*&PTAX_SEIS.,FI_TAXCR,SINVRTOT*&PTAX_S ITR.,LLIR_RESTRICT_AMT_TOT*&PTAX_LLIR.); 
/* total tax after tax credits/reducers */ 
tottaxpost = max(0,tottaxpre-taxcr); 
/* initialise total tax after tax credits */ 
tottax = 0; 
/* re-initialise marginal rate indicator */ 
/* will be re-computed below with respect to tax due (not taxable  income as above) */ 
/* e.g. if taxpayer has taxable income in HR band, but tax  credits/reducers cover the HR tax liability due 
then the taxpayer will be assigned as BR */ 
taxtype = 0; 
/* marginal rate on earnings */ 
mtr_tottax = 0; 
/* assign 2D elements in array for tax liabilities (after tax  credits) by (income stream,band);  
and sum tottax and assign marginal rate indicator */ 
do s = 1 to &PTAX_NSTREAMS.;
OFFICIAL 
do b = 1 to &PTAX_NBANDS.; 
/* allocate tax credits relief proportionately by  
(stream,band) */ 
if tottaxpre > 0 and s = 1 then tax(s,b) =  
round(((taxpre(s,b)/tottaxpre)*tottaxpost),0.01); 
else if tottaxpre > 0 and s > 1 then tax(s,b) =  
round((taxpre(s,b)/tottaxpre)*tottaxpost,0.01); 
else tax(s,b) = 0; 
/* if stream = dividends stream and user has specified  
liabilities basis via %ptmrun option #divtc{false},  
add dividend tax covered by the dividend tax credit  
*/ 
if s = &PTAX_DIVSTREAM. and &divtc. = 0 then tax(s,b) =  
round(sum(tax(s,b),taxinc2(s,b)*&PTAX_DTCR.),0.01); 
/* update total tax and tax in this tax band variables */ 
tottax = round(sum(tottax,tax(s,b)),0.01); 
taxb(b) = round(sum(taxb(b),tax(s,b)),0.01); 
/* update marginal rate indicator */ 
if tax(s,b) > 0 and b > taxtype then taxtype = b; 
/* assign MTR variable (for earnings) */ 
if s = 1 and tax(s,b) > 0 then mtr_tottax =  
100*taxrate(1,b); 
end; 
end; 
/* revised pension tax code */ 
/* charge applies to any excess of pension savings over the annual  limit (shown in input variable PSAV_XS) */ 
/* in this implementation, PTM+ 'stacks' excess pensions saving on  top of other taxable incomes  
in order to determine the tax rate that will apply */ 
%macro tax_pench(); 
/* initialise tax on excess pension savings at zero */ 
tax_pench = 0; 
if PSAV_XS > 0 then do; 
temp_psav_xs = PSAV_XS; 
/* step through tax bands */ 
%do b = 1 %to &PTAX_NBANDS.; 
/* allocate excess pension savings to bands from  
bottom up */ 
/* note: at this point, array taxlim holds  
remaining widths of bands available 
following earlier allocation of other taxable  
incomes */ 
psav_xs_in_band = min(temp_psav_xs,taxlim(&b.)); 
temp_psav_xs = temp_psav_xs - psav_xs_in_band; 
/* determine tax rate to be applied */ 
/* note: code assumes UK NSND rates are relevant,  
and further assumes these are stream one */ 
/* uses UK NSND basic rate for tax bands below BRL,  
*/ 
if &b. < &PTAX_BRLIM. then tax_pench_rate =  
&&PTAX_RATE_S1_B&PTAX_BRLIM.; 
else tax_pench_rate = &&PTAX_RATE_S1_B&b.; 
/* compute tax applying to excess savings in this  
tax band and add to relevant output variables */ 
tax_psav_xs_in_band = psav_xs_in_band *  
tax_pench_rate; 
tax_pench = tax_pench + tax_psav_xs_in_band; 
tax(1,&b.) = tax(1,&b.) + tax_psav_xs_in_band;
OFFICIAL 
taxb(&b.) = taxb(&b.) + tax_psav_xs_in_band; 
%end; 
end; 
/* add excess pensions saving charge to tottax */ 
tottax = tottax + tax_pench; 
%mend tax_pench; 
%tax_pench; 
/* assign elements in the tptax by tax band array */ 
do i = 1 to &PTAX_NBANDS.; 
if taxtype = i then tptax(i) = tottax;  
else tptax(i) = 0; 
end; 
/* adjust MTR variable for tapering effects */ 
if agetaper = 1 then mtr_tottax = mtr_tottax * (1+&PTAX_AILTR.); if pataper = 1 then mtr_tottax = mtr_tottax * (1+&PTAX_PATR.); 
if mcataper = 1 then mtr_tottax = mtr_tottax +  
100*&PTAX_MCAR.*&PTAX_MCATR.; 
/* set PTM/NS marginal rate indicator to zero */ 
/* assigned in mrgcode module called next */ 
mrg_code = " "; 
/* ## HICB from 2012-13 Jan 2013 (Does not affect marginal rate) *  Must be placed at end of INCTAX Module ## */ 
%macro HICB(); 
if iad > &PTAX_HICB_LIMIT. then do; 
if CB_CHRGE > 0 then do; 
NO_STEPS = INT((iad - 
&PTAX_HICB_LIMIT.)/&PTAX_HICB_STEP.); 
HICB_RATE = MIN(1, &PTAX_HICB_STEP_RATE. * NO_STEPS); 
TAX_HICB = CB_CHRGE * HICB_RATE; 
/* tottax = tottax + TAX_HICB; DE-ACTIVATED BUT LEFT SO  CAN SWITCH BACK IN */ 
end; 
end; 
%mend HICB; 
%HICB; 
end; /* last.sref */
OFFICIAL