Material Facts in the Debate Over Twombly and Iqbal

56 Pages Posted: 1 Mar 2015 Last revised: 19 Apr 2016

See all articles by Jonah B. Gelbach

Jonah B. Gelbach

University of Pennsylvania Law School

Date Written: 2016


This paper presents empirical evidence concerning the adjudication of defendant-filed summary judgment motions from nearly 2,000 randomly selected employment discrimination and contracts cases to try to assess Twombly and Iqbal’s performance in filtering cases according to merit. I first explain how such data might be helpful in such an assessment, taking into account the possibility that parties’ behavior might have changed following Twombly and Iqbal.

I then report results indicating that even using this large collection of data -- the most comprehensive data assembled to date to address this question -- we cannot tell whether “TwIqbal” supporters or critics are more correct about the efficacy of the new plausibility pleading regime in the pre-discovery filtering of cases according to merit. This null result points to the very real possibility that plausibility pleading’s case-quality effects -- a quintessential empirical question -- simply can't be answered using data.

This paper’s basic message, then, is that empirical evidence is unlikely to settle the debate over the case-quality effects of the new pleading regime ushered in by Twombly and Iqbal.

Keywords: pleading, plausibility, summary judgment, Twombly, Iqbal, civil procedure, empirical

JEL Classification: K4, K41

Suggested Citation

Gelbach, Jonah B., Material Facts in the Debate Over Twombly and Iqbal (2016). Stanford Law Review, Vol. 68, P. 369, 2016; U of Penn, Inst for Law & Econ Research Paper No. 15-11. Available at SSRN: or

Jonah B. Gelbach (Contact Author)

University of Pennsylvania Law School ( email )

3501 Sansom Street
Philadelphia, PA 19104
United States

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