program define logitdropvar
	version 14
	syntax anything

	clear all
	set obs 1000
	forvalues i=1/4 {
		generate x`i' = runiform(-`anything',`anything') // x's independent and balanced
		}
	egen ylo = rowtotal(x*)
	generate ypr = invlogit(ylo)
	generate y = runiform() > ypr

	quietly logit y x*
	estimates store four
	quietly logit y x1-x3
	estimates store three
	quietly logit y x1-x2
	estimates store two
	quietly logit y x1
	estimates store one

	estimates table four three two one, se stats(bic r2_p)
	coefplot (four)(three)(two)(one), drop(_cons) ///
		title("x's from -`anything'/`anything'")
end

logitdropvar 3 // each x reaches into the logit's tails
logitdropvar 1 // the x's jointly reach into the tails
logitdropvar 0.5
logitdropvar 0.25
logitdropvar 0.125 // the joint range of the x's is mostly in the
	// "linear" portion of the logit