下面是我断点回归的结果，选取的是1倍（也就是最优带宽）和2倍带宽，但是所得的结果数据完全相同，请问哪位知道这样的结果有效么？

Three variables specified; jump in treatment  

at Z=74 will be estimated. Local Wald Estimate

is the ratio of jump in outcome to jump in treatment.

Assignment variable Z is x

Treatment variable X_T is Dt

Outcome variable y is volt

Command used for graph: lpoly; Kernel used: rec

Bandwidth: 1.0020199; loc Wald Estimate: .

Bandwidth: 2.0040398; loc Wald Estimate: -.000081

Estimating for bandwidth 2.004039832923526

Estimating for bandwidth 2.004039832923526

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        volt |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]

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       numer |  -.0000135   .0000694    -0.19   0.846    -.0001496    .0001226

       denom |   .1666667   .2012691     0.83   0.408    -.2278136    .5611469

       lwald |   -.000081   .0003183    -0.25   0.799    -.0007049    .0005429

    numer200 |  -.0000135   .0000694    -0.19   0.846    -.0001496    .0001226

    denom200 |   .1666667   .2012691     0.83   0.408    -.2278136    .5611469

    lwald200 |   -.000081   .0003183    -0.25   0.799    -.0007049    .0005429

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