/* Social Security Supplementary Income for United States -
Based on Chapter 21 of SS Hanbook.
---------------------------------------------------- */

program define SSiBenefit,	
	syntax varlist [if], gen(namelist)
	marksample touse
	tokenize `varlist'
	#delimit;
	tempvar hy ass mar yr;
	///1. Assign Data to Variables -------------------
	
	qui gen `hy'    = `1'  if `touse';	
	qui gen `ass'	 = `2'  if `touse';
	qui gen `mar'	 = `3'  if `touse';	
	qui gen `yr'  = `4'  if `touse';	

	/// 2.A Important Indicators ----------------------
	tempname fbr_sing fbr_coup ass_sing ass_coup;
	scalar `fbr_sing' = 637*12;
	scalar `fbr_coup' = 956*12;
	scalar `ass_sing' = 2000;
	scalar `ass_coup' = 3000;
	
	tempvar inctest asstest test;
	qui gen `inctest' = `hy'<=`fbr_sing' if `touse'&`mar'==0;
	qui replace `inctest' = `hy'<=`fbr_coup' if `touse'&`mar'==1;	
	
	qui gen `asstest' = `ass'<=`ass_sing' if `touse'&`mar'==0;
	qui replace `asstest' = `ass'<=`ass_coup' if `touse'&`mar'==1;
	qui gen `test' = `inctest'*`asstest' if `touse';
	
	tempvar ssiben;
	qui gen `ssiben' = `test'*max(`fbr_sing'-`hy',0) if `touse'&`mar'==0;
	qui replace `ssiben' = `test'*max(`fbr_coup'-`hy',0) if `touse'&`mar'==1;
	
	tokenize `gen';
	qui gen `1' = `ssiben' if `touse';
end;