该数据没必要纠偏。

有一个老外也遇到同样的问题，http://www.stata.com/statalist/archive/2005-12/msg00438.html网站对他的回复是如下这样的，大侠能否解释一下该回答是否可信，不太明白
> > 1)  Somehow, when I run the full MLE heckman model:
> > heckman y x1 x2 x3, select (x1 x2 x3)
> > I get the following error:
> > Dependent variable never censored due to selection:
> > model would simplify to OLS regression
>
> -heckman- assumes that an observation is censored if y has a missing value. You ensured that there
> are no missing values, but by doing so prevented -heckman- from identifying the censored
> observations. So just taking the log of y would be enough in your case.

你看看heckman帮助的例子中的变量的数据，对比一下自己的数据就知道那里的问题了。