In the wake of Twombly and Iqbal, a number of studies have been conducted to determine their effects on dismissal practice in federal civil cases. However, because of coding and collection difficulties, those studies have tended to code whole cases rather than claims--leading to the ambiguous coding category of “mixed” dismissals and to problems in characterizing the nature of the dispute--and have failed to distinguish between legal sufficiency and factual sufficiency, potentially masking important detail about the effects of the pleadings changes.

This paper begins to fill in that detail. I compiled an original dataset of district court opinions and coded each claim—rather than whole case—subject to an adjudicated Rule 12(b)(6) motion. For each claim, I also determined whether the court resolved the motion on grounds of legal or factual sufficiency. This methodology opened an unprecedented level of granularity in the data.

The data reveal statistically significant increases in the dismissal rate overall and in a number of subsets of claims. I also find an increase in the prevalence and effectiveness of factual-insufficiency arguments for dismissal. Perhaps surprisingly, I find a decrease in the prevalence and effectiveness of legal-insufficiency arguments for dismissal. These data and insights on the rationales of dismissals are new to the literature and suggest that Twombly and Iqbal are affecting both the strategy employed by movants and the rationale for deciding motions to dismiss.