capture program drop fix1psu
program define fix1psu, sortpreserve
*! v1.1 gmh aug 9 2004
syntax [if] [in]
qui svyset
local psu "`r(psu)'"
global oldpsu "`psu'"
if "`psu'"=="" {
	tempvar id
	qui gen `id' = _n
	local psu "`id'"
	}
	/*
capture which bign
if _rc ~=0 {
	di in gr "command " in ye "bign" in gr  " is not installed."
	di in gr "click " `"{net "describe http://www.unc.edu/~gholmes/stata/smn": here} "'
	exit
	}
	*/

local strata "`r(strata)'"
global oldstr "`strata'"

tempvar touse
qui gen `touse' =1 `if' `in'

qui count if `strata'==99999 & `touse'==1
capture assert r(N)==0 
if _rc~=0 {
	di in ye "`strata'" in gr " equals 99999 in " in ye `r(N)' in gr " cases"
	exit
	}




tempvar by_psu_str by_str psusinstr

qui egen `by_psu_str'=sum(1) `if' `in' , by( `strata' `psu')
qui egen `by_str'=sum(1) `if' `in' , by( `strata' )


*qui bign `strata' `psu' `if' `in', n(`by_psu_str')
*qui bign `strata' `if' `in', n(`by_str')

capture drop _strata
qui gen _strata = `strata'

qui count if `by_psu_str'==`by_str' & `touse'==1

qui replace _strata = 99999 if `by_psu_str'==`by_str'

di in gr "new stratum = " in ye " _strata " in gr "recoded to 99999 in " in ye `r(N)' " cases " 
svyset , strata(_strata)

end