Gelbach: Can Empirical Evidence Tell Us the Effects of Twombly & Iqbal?

Material Facts in the Debate Over Twombly and Iqbal"  
68 Stan. L. Rev. ___ (2016) (Forthcoming)

JONAH B. GELBACH, University of Pennsylvania Law School

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.