(* PS12.1, using DATA4-5 to illustrate Example 12.1 *)
genr y = ln(wlfp/(100-wlfp))
(* estimate the logit model *)
ols y 0 yf educ ue urb wh
(* save predicted values *)
genr lyhat=yhat
(* take antilog and correct for bias in log model *)
genr y1=exp(lyhat+($ess/(2*$df)))
(* predict the participation rate and compute the errors *)
genr wlfphat = 100*y1/(1+y1)
genr error = wlfp - wlfphat
(* compute ESS and adjusted model selection criteria for logit model *)
genr ess = sum(error*error)
criteria ess 50 6
(* estimate linear model *)
ols wlfp 0 yf educ ue urb wh
