没有人理我吗？拜托了，5555555555555555。

economic data often have measurement error.It may be caused by ambiguous question or intentionally false responses.If a question of survey is do you drink when you drive?will you response truely?Of couse not.

现在大概理解，应该是“变量选择错误”的意思吧。

Measurement errors would be better understandable. Usually it refers to covariates (X variables) containing random or not random measurement errors. In this case, OLS assumption of E(x * e)=0 is no longer true.

是变量含有测量误差的意思！