Hi STATALIST,

Following program supposed to give me 100 different MSEs, but it produced 100 same MSEs. could anyone please help me to find out the problem?

Regards,

Code:
clear
clear matrix
capture log close
pause on

log using "C:\internal validation CT.log", text replace

capture program drop nfoldmseCT
program define nfoldmseCT
    local N `2'
    local i=1
    postfile mysim mse using nfoldmseCT-estimates, replace
    set seed 34561
 while `i' <= `1' {
  drop _all
  
  use "C:\internal validation CT.dta", clear
    
  quietly nbreg CTexamsnumber CTunitsdensitypermillionp  un2016poulation65years undp2017humandevelopmentinde if sample==0 , exposure(un2015populationtotal1000) irr vce(robust)
             
   drop if sample==0
            sample `N', count
            predict predict_rate_CT if sample==1, ir
            gen diff =.
            replace diff = (predict_rate_CT - CTexamsdensityperthousand)^2  if sample==1
          
   quietly  summarize diff, detail
           local mse = (r(mean))

    post mysim  (`mse')
      local i=`i'+1
      }
 postclose mysim
 use nfoldmseCT-estimates, clear
end
nfoldmseCT 100 77
 /* 100 samples of size 77 */

list

summarize  mse

Array