用psm匹配失败 全部都没有匹配上 结果显示如下图 请问是为什么原因啊
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qfii_dum | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
size | -7.519586 . . . . .
lev | -1182.403 . . . . .
growth | 22.18935 . . . . .
tat | -13.18203 . . . . .
cr | -1.395568 . . . . .
top_1 | -2158.986 . . . . .
cashflow2 | -20.05036 . . . . .
state | 3.734833 . . . . .
indep | -1.830002 . . . . .
_cons | 274.1287 . . . . .
Note: 107799 failures and 11797 successes completely determined.
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Variable Sample | Treated Controls Difference S.E. T-stat
----------------------------+-----------------------------------------------------------
roa Unmatched | .000411116 .029777504 -.029366387 .000401087 -73.22
ATT | . . . . .
psmatch2: | psmatch2: Common
Treatment | support
assignment | Off suppo On suppor | Total
-----------+----------------------+----------
Untreated | 0 107,799 | 107,799
Treated | 11,797 0 | 11,797
-----------+----------------------+----------
Total | 11,797 107,799 | 119,596