From Blackstone's Ratio to the Conviction Ratio

39 Pages Posted: 27 Jan 2016 Last revised: 8 Feb 2016

See all articles by Richard M. Hynes

Richard M. Hynes

University of Virginia School of Law

Date Written: January 26, 2016


Blackstone’s Ratio tells courts to focus more on preventing wrongful convictions than wrongful acquittals. Some critics argue that legislatures undermine the protection that courts afford to the wrongfully accused by, among other things, increasing sentences. A strong form of this critique suggests that the disproportionate focus on wrongful convictions leaves the wrongfully accused worse off. This essay uses a simple model to assess the plausibility of this critique and finds that Courts minimize the innocents’ suffering by minimizing the Conviction Ratio (the probability of convicting an innocent defendant divided by the probability of convicting a guilty defendant). This result holds even if one assumes that most cases are resolved through plea-bargaining. Only those who believe that our criminal justice system convicts many innocent defendants should find the anti-Blackstone critique convincing. This essay further shows that minimizing the Conviction Ratio may also minimize the total social costs of crime and punishment.

Keywords: Criminal Law, Criminal Procedure, Blackstone's Ratio

JEL Classification: K14, K42

Suggested Citation

Hynes, Richard M., From Blackstone's Ratio to the Conviction Ratio (January 26, 2016). Virginia Public Law and Legal Theory Research Paper No. 17, Available at SSRN: or

Richard M. Hynes (Contact Author)

University of Virginia School of Law ( email )

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Charlottesville, VA 22903
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