// PS 5 solutions 

use "credit_access.dta", clear 

// 1.5 
g dummy_above = (psut1 >= 475) if psut1 != .
g dif = psut1 - 475 
g interact = dif*dummy_above
 
// 1.6  
reg enrolt1 dummy_above dif interact if abs(dif)<=44, r

// 1.7
reg enrolt1 dummy_above dif interact if abs(dif)<=22, r
reg enrolt1 dummy_above dif interact if abs(dif)<=88, r
reg enrolt1 dummy_above dif interact if abs(dif)<=220, r

// 1.9 
use "credit_access2.dta", clear 
ivreg everenroll1  (everelig1=dummy_above) dif interact if abs(dif)<=44, r