Data Problems in Econometrics
This review of data problems in econometrics has been prepared for the Handbook of Econometrics (Vol. 3, Chap. 25, forthcoming). It starts with a review of the ambivalent relationship between data and econometricians, emphasizing the largely second-hand nature of economic data and the consequences that flow from the distance between econometricians as users of data and its producers. Section II describes the major types of economic data while Section III reviews some of the problems that arise in trying to use such data to estimate model parameters and to test economic theories. Section IV reviews the classical errors in variables model and its applicability to micro-data, especially panel data. Section V discusses missing data models and methods and illustrates them with an empirical example. Section VI focuses on the problem of estimating models in the absence of a full history, suggests a possible range of solutions, and provides again an empirical example: using a short panel to investigate the weights to be used in constructing a correct "capital" measure. The chapter closes (Section VII) with some final remarks on the existential problem of econometrics: life with imperfect data and inadequate theories.