前辈们好,我的论文中应用PSM方法,跑出的pscore有很多负值。这是为什么呢?这个倾向得分,不是一个条件概率吗,概率应该是0到1之间啊,我看论文里,大家的共同支撑域也都是0-1之间的。求前辈们赐教!
set seed 20220525
gen tem=runiform()
sort tem
psmatch2 equipment1 gender age marrige religion education income2 health chronicdisease internet,outcome(depression)logit ties ate common odds
pstest gender age marrige religion education income2 health chronicdisease internet,both graph
***求共同支撑域
sum _pscore if _treated==1
sum _pscore if _treated==0
sum _pscore
Variable | Obs Mean Std. Dev. Min Max
-------------+---------------------------------------------------------
_pscore | 5,684 -.9920107 1.209943 -4.668199 2.631621