On 22nd June 2016, Prof. Yingyao Hu from the Department of Economics at Johns Hopkins University, was invited to give a lecture on “Econometrics of Unobservables”. Prof. Hu first explained the differences between variables in econometric models and variables in reality. Additionally, there are many critical variables in theoretical models are unobservable, such as permanent income in consumption function, ability of workers in wage function, belief in cognitive model, and unobserved heterogeneity in auction model, while the measuring error of these variables may lead to a serious endogeneity problem. Prof. Hu suggested that the Measuring Error Model can help to address these problems in the lecture.