*!                                                      (STB-29: sg48)
*! predlog--predict log-transformed variables in the original metric
program define predlog
    version 4.0
    local varlist "req ex min(2)"
    local if "opt"
    local in "opt"
    local options "FPredict"
    parse "`*'"
    parse "`varlist'", parse(" ")
    local lhs "`1'"
    mac shift
    local rhs "`*'"
    tempvar logdepv RESID RESID2 yhatraw
    qui gen `logdepv'=log(`lhs')
    qui fit `logdepv' `rhs' `if' `in'
    local rmse=_result(9)
    if "`fpredict'"=="" { qui predict `yhatraw' }
    else {qui fpredict `yhatraw' }
    qui fpredict `RESID', res
    qui gen `RESID2'=exp(`RESID')
    qui su `RESID2'
    local meanres _result(3)
    capture drop YHATRAW YHTNAIVE YHTSMEAR
    qui gen YHATRAW=exp(`yhatraw')
    la var YHATRAW "Straight Retransformation"
    qui gen YHTNAIVE=exp(`yhatraw'+(`rmse'^2/2))
    la var YHTNAIVE "Naive Retransformation"
    qui gen YHTSMEAR=YHATRAW*`meanres'
    la var YHTSMEAR "Duan's Smearing Retransformation"
end