代码：rd dsalary1 ifout difference, gr mbw**#使用1,0,5,2倍带宽默认三角核进行模糊断点回归并画图

错误：A predicted value of treatment at cutoff lies outside feasible range;
switching to local mean smoothing for treatment discontinuity.
Warning: Variance matrix is nonsymmetric or highly singular.
using -ivreg- to estimate due to failure of -suest-