The Biases of Experts: An Empirical Analysis of Expert Witness Challenges

46 Pages Posted: 23 Aug 2019

See all articles by Jason Chin

Jason Chin

Sydney Law School

Michael Lutsky

University of Toronto - Faculty of Law

Itiel Dror

University College London (UCL)

Date Written: August 21, 2019


Biased expert witnesses pose a distinct challenge to the legal system. In the criminal sphere, they have contributed to several wrongful convictions, and in civil cases, they can protract disputes and reduce faith in the legal system. This has inspired a great deal of legal-psychological research studying expert biases and how to mitigate them. In response to the problem of biased experts, courts have historically employed procedural mechanisms to manage partiality, but have generally refrained from using exclusionary rules. Canada diverged from this position in 2015, developing an exclusionary rule in White Burgess Langille Inman v Abbott and Haliburton Co. In this article, we assembled a database of 229 Canadian bias cases pre- and post-White Burgess to evaluate the impact that this case had on the jurisprudence. The data suggests that White Burgess increased the frequency of challenges related to expert biases, however, did not noticeably affect the proportion of experts that were excluded. This suggests that the exclusionary rule introduced in White Burgess did not significantly impact the practical operation of expert evidence law, as it pertains to bias. We conclude by recommending that one way for courts to better address the problem of biased experts is to recognize the issue of contextual bias.

Keywords: expert evidence, bias, cognitive bias, contextual bias, adversarial bias

JEL Classification: K10, K14, K41

Suggested Citation

Chin, Jason and Lutsky, Michael and Dror, Itiel, The Biases of Experts: An Empirical Analysis of Expert Witness Challenges (August 21, 2019). Manitoba Law Journal, Forthcoming. Available at SSRN:

Jason Chin (Contact Author)

Sydney Law School ( email )

New Law Building, F10
The University of Sydney
Sydney, NSW 2006

Michael Lutsky

University of Toronto - Faculty of Law ( email )

78 and 84 Queen's Park
Toronto, Ontario M5S 2C5

Itiel Dror

University College London (UCL) ( email )

35 Tavistock Square
London WC1H 9EZ, WC1H 9EZ
United Kingdom


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