Iatrogenic Specification Error : A Cautionary Tale of Cleaning Data

Arbeitspapier

In empirical research it is common practice to use sensible rules of thumb for cleaning data. Measurement error is often the justification for removing (trimming) or recoding (winsorizing) observations whose values lie outside a specified range. We consider a general measurement error process that nests many plausible models. Analytic results demonstrate that winsorizing and trimming are only solutions for a narrow class of measurement error processes. Indeed, for the measurement error processes found in most social-science data, such procedures can induce or exacerbate bias, and even inflate the variance estimates. We term this source of bias ?Iatrogenic? (or econometrician induced) error. Monte Carlo simulations and empirical results from the Census PUMS data and 2001 CPS data demonstrate the fragility of trimming and winsorizing as solutions to measurement error in the dependent variable. Even on asymptotic variance and RMSE criteria, we are unable to find generalizable justifications for commonly used cleaning procedures.

Object Details

• Language: Englisch

References and Relationships

• Bibliographic citation: Series: IZA Discussion Papers ; No. 1093

Classification and Topics

• Classification: Wirtschaft
• Subject: measurement error models ; trimming ; winsorizing ; Modell-Spezifikation ; Statistischer Fehler ; Bias ; Theorie

Contributors, Places and Time

• Event: Geistige Schöpfung
• (who): Bollinger, Christopher R. ; Chandra, Amitabh
• Event: Veröffentlichung
• (who): Institute for the Study of Labor (IZA)
• (where): Bonn
• (when): 2004

Further information

• Handle: http://hdl.handle.net/10419/20328
• Last update: 10.03.2025, 11:41 AM CET