How Evidence of Subsequent Remedial Measures Matters

53 Pages Posted: 17 Apr 2019 Last revised: 25 Nov 2019

See all articles by Bernard Chao

Bernard Chao

University of Denver Sturm College of Law

Kylie Santos

University of Denver; Burns, Figa & Will, PC

Date Written: April 17, 2019


Evidence Rule 407 prohibits plaintiffs from introducing evidence of subsequent remedial measures to show that the defendant is to blame. Among its purported justifications, the rule prevents hindsight bias from unduly influencing jury decisions. Nonetheless, plaintiffs often take advantage of the rule’s numerous exceptions to introduce evidence of remedial measures for other purposes (e.g. to prove feasibility). Fearing that the exceptions could swallow the rule, some courts will even exclude evidence that fits into one of these exceptions because it is ostensibly too prejudicial. Alternatively, other courts instruct juries that they should only use the evidence for the limited permissible purpose, but not for proving blameworthiness.

This complex scheme makes several assumptions about how evidence of remedial measures and the accompanying limiting instructions influence juries. Although many studies have examined hindsight bias in other contexts, and one older study looked at Evidence Rule 407 in particular, these studies typically used short written vignettes with small sample sizes. Moreover, none of these studies examined how subsequent measures impact damages. We sought to test these concepts in robust fashion by conducting two separate experiments using videos that included rich fact patterns including arguments from both parties and jury instructions. In the end, over one thousand seven hundred mock jurors rendered verdicts on liability, contributory negligence, and damages.

As expected, evidence of subsequent remedial measures helped plaintiffs win more often. But surprisingly, our results also suggested that taking remedial measures may lower damages, thereby counteracting the increased liability findings. We also studied the efficacy of two limiting jury instructions. In one experiment, a limiting instruction with an explanation reduced but did not eliminate the effects of evidence of subsequent remedial measures. The instruction with explanation was also consistently more effective than the simple limiting instructions, but these results were not statistically significant. We hypothesize about the potential reasons for our various results and discuss what they mean for policymakers, litigants and future researchers that may wish to explore this subject in more depth.

Keywords: Evidence, jury instructions, subsequent remedial measures, empirical, hindsight bias, jury

JEL Classification: K13

Suggested Citation

Chao, Bernard H. and Santos, Kylie and Santos, Kylie, How Evidence of Subsequent Remedial Measures Matters (April 17, 2019). 84 Missouri Law Review 609 (2019), U Denver Legal Studies Research Paper No. 19-07, Available at SSRN:

Bernard H. Chao (Contact Author)

University of Denver Sturm College of Law ( email )

2255 E. Evans Avenue
Denver, CO 80208
United States

Kylie Santos

University of Denver

2255 E Evans Ave
Denver, CO 80210
United States

Burns, Figa & Will, PC ( email )

6400 S Fiddlers Green Circle
Suite 1000
Greenwood Village, CO 80111
United States

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