各位大神,求教个问题,在用广义倾向得分匹配(GPS)分析时,老是出现两个问题:1. The assumption of Normality is not statistically satisfied at .05 level
It is advisable to try a different trasformation of the treatment variable
2. 1 group found, 2 required
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ESTIMATE OF THE GENERALIZED PROPENSITY SCORE
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Generalized Propensity Score
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Algorithm to estimate the generalized propensity score
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Estimation of the propensity score
The BoxCox transformation of the treatment variable cen is used
T
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Percentiles Smallest
1% 1.166742 1.166742
5% 1.179652 1.166742
10% 1.179652 1.166742 Obs 22,231
25% 1.219498 1.166742 Sum of Wgt. 22,231
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End of the algorithm to estimate the gpscore
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The set of the potential treatment values is divided into 6 intervals
The values of the gpscore evaluated at the representative point of each
treatment interval are divided into 5 intervals
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Summary statistics of the distribution of the GPS evaluated
at the representative point of each treatment interval
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Variable | Obs Mean Std. Dev. Min Max
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gps_1 | 22,231 4.543274 .237251 2.885289 5.826589
Variable | Obs Mean Std. Dev. Min Max
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gps_2 | 22,231 4.774775 .2135613 3.095474 5.918881
Variable | Obs Mean Std. Dev. Min Max
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gps_3 | 22,231 3.037522 .2429328 1.566484 4.691811
Variable | Obs Mean Std. Dev. Min Max
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gps_4 | 22,231 2.071809 .2117767 .9311559 3.648537
Variable | Obs Mean Std. Dev. Min Max
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gps_5 | 22,231 1.608863 .1853206 .6689561 3.050296
Variable | Obs Mean Std. Dev. Min Max
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gps_6 | 22,231 1.301614 .163156 .5098148 2.61117
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Test that the conditional mean of the pre-treatment variables given the generalized
propensity score is not different between units who belong to a particular treatment
interval and units who belong to all other treatment intervals
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1 group found, 2 required