Selection Bias in Innovation Studies: A Simple Test

de Rassenfosse, Gaétan; Schoen, Anja; Wastyn, Annelies

doi:10.2139/ssrn.1969134

Selection Bias in Innovation Studies: A Simple Test

25 Pages Posted: 8 Dec 2011 Last revised: 10 May 2013

See all articles by Gaétan de Rassenfosse

Gaétan de Rassenfosse

Ecole Polytechnique Fédérale de Lausanne

Annelies Wastyn

KU Leuven - Department of Managerial Economics, Strategy and Innovation

There are 4 versions of this paper

Date Written: December 18, 2012

Abstract

The study of the innovative output of organizations often relies on a count of patents filed at one single office of reference such as the European Patent Office (EPO). Yet, not all organizations file their patents at the EPO, raising the specter of a selection bias. Using novel datasets of the whole population of patents by Belgian firms and German universities, we show that the single-office count results in a selection bias that affects econometric estimates of invention production functions. We propose a methodology to evaluate whether estimates that rely on the single-office count are affected by a selection bias.

Keywords: knowledge production function, patent count, R&D, selection bias

JEL Classification: O31, C18, C52, C81

Suggested Citation: Suggested Citation

de Rassenfosse, Gaétan and Schoen, Anja and Wastyn, Annelies, Selection Bias in Innovation Studies: A Simple Test (December 18, 2012). Available at SSRN: https://ssrn.com/abstract=1969134 or http://dx.doi.org/10.2139/ssrn.1969134