换了initial 之后，还是运行有错
. xtlsdvc   il lnec et cover ed t, initial(ah) bias(3) vcov(50)
note: variable cover is time-invariant over the
      estimation sample and has been discarded
Bias correction initialized by Anderson and Hsiao estimator
note: Bias correction up to order O(1/NT^2)

no observations
command -> xtlsdvc_b il lnec et ed t , initial(ah) bi(3)
an error occurred when command was executed on original dataset
please rerun and specify the trace option to see a trace of the commands executed
r(2000);


Search of official help files, FAQs, Examples, SJs, and STBs

[P]     error . . . . . . . . . . . . . . . . . . . . . . . . Return code 2000
        no observations;
        You have requested some statistical calculation and there are
        no observations on which to perform it.  Perhaps you specified
        if or in and inadvertently filtered all the data.

(end of search)

估计是数据格式的问题

你好，请问一下数据格式是哪种标准才会不会出现此问题呢？谢谢，我也不知道数据哪里有问题

请问您后面解决了吗，我也出现这样的问题

您好，请问楼主最后出文章了吗？ 可否分享 学习下哈/ 我也在写这方面文章 是长面板 不太会方法。 谢谢了！