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Mala Prohibita and Proportionality


What is the proportionate punishment for conduct that is neither harmful nor wrongful? A likely response to that is that one ought not to be punished at all for such conduct. It is, however, common for the state to punish harmless conduct the wrongfulness of which is not always apparent. Take, for example, the requirement that those who give investment advice for compensation do so only after registering as an investment advisor. Advising a person on how to invest his or her funds and accepting a fee for the advice without registering with the government does not seem harmful or wrongful, so long as no fraud is involved, the relevant parties understand the relevant risks, and so on. But practicing investment advising without registering is a crime for which one may be convicted and punished. When one thinks of crimes, paradigmatic offenses are crimes like murder, rape, and robbery, but offenses like failure to register as an investment advisor are different. But in what way? One standard explanation is the distinction between two types of offenses, malum in se and malum prohibitum. Some offenses, like murder, are wrongs “in themselves” (“in se”) whereas other offenses, like investment advising without registering as an advisor, are wrongs because they have been prohibited (“prohibitum”). The question this Essay asks is how we should think about proportionality of punishment when punishing such mala prohibita offenses. This Essay presents a framework for such proportionality determinations and raises some challenges such a framework would need to confront.

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  1. 1.

    15 USC s. 80b-3 (2019) (“[I]t shall be unlawful for any investment adviser, unless registered under this section, … to make use of the mails or any means or instrumentality of interstate commerce in connection with his or its business as an investment adviser.”); 15 USC s. 80b-2 (2019) (“‘Investment adviser’ means any person who, for compensation, engages in the business of advising others … as to the advisability of investing in, purchasing, or selling securities …”); 15 USC s. 80b-17 (2019) (“Any person who willfully violates any provision of this subchapter, or any rule, regulation, or order promulgated by [the Securities and Exchange] Commission under authority thereof, shall, upon conviction, be fined not more than $10,000, imprisoned for not more than 5 years, or both.”).

  2. 2.

    “Proportionality” can mean different things, see, e.g., Youngjae Lee, “The Constitutional Right Against Excessive Punishment”, Virginia Law Review 91 (2005): pp. 737–741, and this Essay assumes that the principle of proportionality means that the harshness of the punishment should reflect our level of condemnation or disapproval of the criminal act. Youngjae Lee, “Why Proportionality Matters”, University of Pennsylvania Law Review 160(6) (2012): pp. 1836–1840. A punishment would be excessive, then, if the degree of condemnation indicated by the amount of punishment were too high relative to the criminal’s culpability. A punishment also would be excessive in situations where it is imposed on a person who has not committed any acts for which the kind of condemnatory expression that accompanies criminal sanction would be appropriate. A corollary to all of this is that the harshness of the punishment should increase as the appropriate level of condemnation or disapproval increases, which in turn should increase as the gravity of the crime increases.

  3. 3.

    Larry Alexander and Kimberly Kessler Ferzan, Reflections on Crime and Culpability: Problems and Puzzles (New York: Cambridge University Press, 2018), p. 83; Larry Alexander and Kimberly Kessler Ferzan, Crime and Culpability: A Theory of Criminal Law (New York: Cambridge University Press, 2009), p. 309.

  4. 4.

    Alexander and Ferzan, Reflections on Crime and Culpability: Problems and Puzzles, pp. 83–84.

  5. 5.

    See, e.g., R.A. Duff, “Perversions and Subversions of Criminal Law”, in R.A. Duff et al. (eds.), The Boundaries of the Criminal Law (Oxford: Oxford University Press, 2010), pp. 88–112; R.A. Duff and S.E. Marshall, “‘Abstract Endangerment’, Two Harm Principles, and Two Routes to Criminalisation”, Bergen Journal of Criminal Law and Criminal Justice 3(2) (2015): pp. 149–157. Alexander and Ferzan call such offenses “preemptive crimes.” Alexander and Ferzan, Reflections on Crime and Culpability: Problems and Puzzles, p. 84 n.2; Alexander and Ferzan, Crime and Culpability: A Theory of Criminal Law, pp. 309–310. Douglas Husak calls them “offenses of risk prevention.” Douglas Husak, Overcriminalization: The Limits of the Criminal Law (New York: Oxford University Press, 2008), p. 38.

  6. 6.

    31 USC. s. 5316(a) (1986) (“[A] person … shall file a report … when the person … knowingly … transports, is about to transport, or has transported monetary instruments of more than $10,000 at one time … from a place in the United States to or through a place outside the United States; or … to a place in the United States from or through a place outside the United States.”); 31 USC s. 5316(b) (1986) (“A report under this section shall be filed at the time and place the Secretary of the Treasury prescribes.”); 31 USC s. 5322 (2001) (“A person willfully violating this subchapter or a regulation prescribed or order issued under this subchapter … shall be fined not more than $250,000, or imprisoned for not more than five years, or both.”); see also United States v. Bajakajian, 524 U.S. 321 (1998).

  7. 7.

    See generally Sandra Guerra Thompson, “The White-Collar Police Force: ‘Duty to Report’ Statutes in Criminal Law Theory”, William & Mary Bill of Rights Journal 11(3) (2009): pp. 3–65; Sungyong Kang, “In Defense of the ‘Duty to Report’ Crimes”, UMKC Law Review 86 (2017): pp. 361–403; Gerard E. Lynch, “The Lawyer as Informer”, Duke Law Journal 491 (1986): pp. 520–521.

  8. 8.

    18 USC s. 1957 (2012) (criminalizing engaging in “a monetary transaction in criminally derived property of a value greater than $10,000 [where the property] is derived from specified unlawful activity”).

  9. 9.

    Morissette v. United States, 342 U.S. 246 (1952); see generally Darryl Brown, “Public Welfare Offenses”, in Markus Dubber and Tatjana Hörnle (eds.), The Oxford Handbook of Criminal Law (New York: Oxford University Press, 2014), pp. 862–883.

  10. 10.

    See, e.g., 31 USC s. 5322 (2001); 15 USC s. 80b-17 (1975); see also Richard Lazarus, “Meeting the Demands of Integration in the Evolution of Environmental Law: Reforming Environmental Criminal Law”, Georgetown Law Journal 83(7) (1995): p. 2441 (“[A]t the federal level, Congress has virtually criminalized civil law by making criminal sanctions available for violations of otherwise civil federal regulatory program.”).

  11. 11.

    A.P. Simester, “Is Strict Liability Always Wrong?”, in A.P. Simester (ed.), Appraising Strict Liability (New York: Oxford University Press, 2005), pp. 21–50; Stuart Green, “Six Senses of Strict Liability: A Plea for Formalism”, in A.P. Simester (ed.), Appraising Strict Liability (New York: Oxford University Press, 2005), pp. 2–9.

  12. 12.

    Others have made similar suggestions. See, e.g., Douglas Husak, “Malum Prohibitum and Retributivism”, in R.A. Duff & Stuart P. Green (eds.), Defining Crimes: Essays on the Special Part of the Criminal Law (Oxford: Oxford University Press, 2005): pp. 74–82 (describing “hybrid offenses”); R.A. Duff, The Realm of Criminal Law (Oxford: Oxford University Press, 2018), pp. 313–322 (“pure and impure”); Stuart P. Green, Lying, Cheating, and Stealing: A Moral Theory of White-Collar Crime (New York: Oxford University Press, 2006), p. 120 (“mala in se and mala prohibita qualities”).

  13. 13.

    This formula does not preclude the possibility of various traditional excuse defenses, such as insanity, duress, and lack of voluntary conduct. In such instances, the values of these variables would amount to zero. What about justification defenses? Is it possible for these numbers to be “negative” in the sense that reasons to engage in these lawbreaking activities outweigh the reasons not to? In such cases, one may be “doing the right thing,” and one who does the right thing of course seems to be not culpable. Two points about this. It is possible for all the numbers to “zero out” because a lawbreaker indeed does the right thing, especially if the relevant conduct meets the requirements of legally recognized justification defenses like self-defense and necessity. However, there may be times when a person appears to have “done the right thing” but still fails to meet the requirements of justification defenses. Then what? In such instances, while Ca is zero, there would still be culpability for disobedience. See infra for more on this. I thank Mihailis Diamantis for raising this question.

  14. 14.

    R.A. Duff, “Crime, Prohibition, and Punishment”, Journal of Applied Philosophy 19(2) (2002): p. 104 (discussing “civic arrogance”); Alexander and Ferzan, Crime and Culpability: A Theory of Criminal Law, p. 311.

  15. 15.

    See, e.g., John Simmons, Moral Principles and Political Obligations (Princeton, New Jersey: Princeton University Press, 1979).

  16. 16.

    Joseph Raz, “The Obligation to Obey the Law”, in Joseph Raz (ed.), The Authority of Law: Essays on Law and Morality (New York: Oxford University Press, 1979), p. 234.

  17. 17.

    Youngjae Lee, “Recidivism as Omission: A Relational Account”, Texas Law Review 87(3) (2008), pp. 1–51; Youngjae Lee, “Punishing Disloyalty? Treason, Espionage, and the Transgression of Political Boundaries”, Law and Philosophy 31(3) (2012): pp. 299–342.

  18. 18.

    John Rawls, A Theory of Justice (Cambridge, Mass.: Harvard University Press, 1971), p. 115.

  19. 19.

    Leslie Green, The Authority of the State (New York: Oxford University Press, 1988); George Klosko, Political Obligations (New York: Oxford University Press, 2005).

  20. 20.

    Duff, The Realm of Criminal Law, p. 333.

  21. 21.

    One place where the legal system has made distinctions of this kind is in the phrase “moral turpitude” in immigration law. 8 USC s. 1227(a)(2)(A)(i) & (ii) (2008) (authorizing removal of aliens convicted of crimes of moral turpitude in certain instances). In Bakor v. Barr, the Eighth Circuit Court of Appeals of the United States ruled that failing to register as a sex offender as required by law is a crime of moral turpitude because “[a]n offender who knowingly fails to register as a sex offender … evades a regulation that is designed to protect vulnerable victims against recidivist sex offenders, and does so with a culpable mental state.” Bakor v. Barr, 958 F.3d 732, 738 (8th Cir. 2020). Some courts that have disagreed with the Bakor court have relied on a similar distinction. See, e.g., Mohamed v. Holder, 769 F.3d 885, 889 (4th Cir. 2014) (“The failure to register as a sex offender … do[es] not implicate any moral value beyond the duty to obey the law.”); Totimeh v. Attorney General of the United States, 666 F.3d 109, 116 (3rd Cir. 2012) (“[F]ailing to register … as a predatory offender is not … an inherently despicable act.”); Efagene v. Holder, 642 F.3d 918, 926 (10th Cir. 2011) (holding that failure to register as a sex offender is not “inherently base, vile, or depraved”). I thank Craig Lerner for alerting me to this line of cases.

  22. 22.

    For a discussion, see Gabriel S. Mendlow, “The Elusive Object of Punishment”, Legal Theory 25(2) (2019): pp. 117–125.

  23. 23.

    NY Vehicle & Traffic Laws s. 1192 (2014).

  24. 24.


  25. 25.

    NY Vehicle and Traffic Laws s. 1193 (2012). Moreover, if a person drives while intoxicated with a child under the age of fifteen in the vehicle as a passenger, then the person is guilty of a felony, and can be imprisoned for up to four years. NY Penal Law s. 70(2)(e) (2019).

  26. 26.

    But see Douglas Husak, “Is Drunk Driving a Serious Offense?”, Philosophy & Public Affairs 23(1) (1994): pp. 52–73.

  27. 27.

    In a study designed to test the effects of alcohol on driving ability, “parameters differed distinctly between the BAC conditions depending on the underlying scenario.” Ramona Kenntner-Mabiala et al., “Driving Performance Under Alcohol in Simulated Representative Driving Tasks”, Journal of Clinical Psychopharmacology 35(2) (2015): p. 140. The test subjects “drove slightly faster under alcohol than under placebo only in the difficult tracking scenario.” Ibid. at 139. Difficult roads resulted in the number of lane departures increasing for those under the influence of alcohol, “whereas in easy tracking scenarios, no lane departure was observed at all.” Ibid. at 140. Difficult scenarios testing the standard deviation of lane position—which refers to swaying from the middle of the road—resulted in a ceiling effect, as sober test subjects had just as much trouble driving in such conditions as drunk subjects. Ibid. See also Arne Helland et al., “Comparison of Driving Simulator Performance with Real Driving After Alcohol Intake: A Randomised, Single Blind, Placebo-Controlled, Cross-Over Trial”, Accident Analysis & Prevention 53 (2013): p.13 (showing that while increasing BAC increased drivers’ tendency to “weave” on the road overall, the effect increased as the difficulty of the test track increased). Circadian sleep propensity can also affect the riskiness of driving after alcohol consumption. See Sergio Garbarino et al., “Circadian Sleep Propensity and Alcohol Interaction at the Wheel”, Journal of Clinical Sleep Medicine 12(7) (2016): p. 1011 (finding that increased sleep propensity led to a higher likelihood of motor vehicle crashes when drunk driving). How unsafe a driver with a high BAC is seems to vary depending on the age and sex of the driver, too. Paul L. Zador et al., “Alcohol-Related Relative Risk of Driver Fatalities and Driver Involvement in Fatal Crashes in Relation to Driver Age and Gender: An Update Using 1996 Data”, Journal of Studies on Alcohol 61(3) (2000): pp. 387–395, 393 (finding that “the relative risk decrease[s] with increasing driver age at every BAC level, for both men and women” and that for the 16–20 age group, “women had lower relative risk than men at every BAC”).

  28. 28.

    One study reported that “more than one third of participants legally intoxicated for driving purposes (37%) reported feeling no buzz or slightly buzzed…,” and “16% of participants who reported no buzz were legally impaired for driving purposes….” Matthew E. Rossheim et al., “Feeling No Buzz or a Slight Buzz Is Common When Legally Drunk”, American Journal of Public Health 106(10) (2016): p. 1761.

  29. 29.

    The “number of drinks” consumed is hardly the only relevant factor to BAC; how quickly the drinks were consumed, the amount of water consumed, whether food was consumed, and the type of alcohol consumed all affected the BAC and the time to peak BAC. Steven M. Teutsch et al., Getting to Zero Alcohol-Impaired Driving Fatalities: A Comprehensive Approach to a Persistent Problem (Washington, D.C.: The National Academies Press, 2018), p. 177. In fact, the amount of fluid intake consumed with alcohol had a higher impact on BAC than the amount of alcohol intake. Julian E. Dilley et al., “Alcohol Drinking and Blood Alcohol Concentration Revisited”, Alcoholism Clinical and Experimental Research 42(2) (2018): pp. 260–269 (2018). BAC increased with the concentration of alcohol, rather than the number of doses of alcohol, effectively proving “that alcohol concentration can influence BAC independent of alcohol dose.” Ibid. Individualized factors were also relevant. See, e.g., Shunji Oshima, “Individual Differences in Blood Alcohol Concentrations After Moderate Drinking Are Mainly Regulated by Gastric Emptying Rate Together With Ethanol Distribution Volume”, Food and Nutrition Sciences 3(6) (2012): pp. 732–737 (2012) (identifying individual differences in “gastric emptying rate” as a significant factor in explaining individual differences in BAC after consuming alcohol). There also appears to be a male–female difference in the rate at which alcohol consumption impacts the BAC. Martin S. Mumenthaler et al., “Gender Differences in Moderate Drinking Effects”, Alcohol Research & Health 23(1) (1999): p. 55.

  30. 30.

    Mendlow, “The Elusive Object of Punishment”: p. 124.

  31. 31.

    NY Vehicle and Traffic Law s. 1192(2) (2014).

  32. 32.

    In this way, this law is similar to statutory rape laws, the message of which may not be, “Do not have sexual relations with someone under the age of consent as legally specified,” but rather, “Do not have sexual relations with a youngish looking person.”

  33. 33.

    For a discussion, see Kimberly Kessler Ferzan, “Defending Imminence: From Battered Women to Iraq”, Arizona Law Review 46 (2004): pp. 233–235; Benjamin Zipursky, “Self-defense, Domination, and the Social Contract”, University of Pittsburgh Law Review 57 (1996), pp. 579–614.

  34. 34.

    Cf. Duff, The Realm of Criminal Law, pp. 67–69.

  35. 35.

    Stuart Green has discussed this problem and has called it “the problem of wrongfulness conflation.” Stuart Green, “Legal Moralism, Overinclusive Offenses, and the Problem of Wrongfulness Conflation”, Criminal Law & Philosophy 14(3) (2020): pp. 417–430. In the statutory rape context, a solution Green suggests is to separate out the two kinds of offenders by convicting them under different statutes, both of which criminalize sex with a juvenile, but one of them has the element “exploitative sex” and the other one does not. The more serious charge would be then “exploitative sex with a juvenile,” and either “non-exploitative sex with a juvenile” or simply “sex with a juvenile” would be the less serious charge. This kind of distinction may improve things, though it is unclear by how much. The state would be now placed in the awkward position of convicting a person that it considers to have engaged in sexual relations with a juvenile in a “non-exploitative” way, in which case it does not seem like there is a wrong to punish at all. If the state tries to avoid the implication by simply not using the “exploitative sex” law and convicts everyone under the law that does not mention the idea of “exploitative sex,” then the problem of wrongness conflation returns. Or, we may end up in that situation through the process of plea bargaining, where the state charges individuals with the “exploitative sex” charge and offers to charge the defendants with the lesser crime in exchange for a guilty plea. The problem of wrongness conflation, again, returns in that world.

  36. 36.

    This description is roughly based on United States v. Joo Hyun Bahn, 16 CR 831 (S.D.N.Y. 2017), but with many modifications. In the actual case, there was a “middle man” between the defendant and the sovereign wealth fund, and it turned out the “middle man” did not know anyone at the fund and was defrauding the defendant. The defendant nevertheless was convicted for violating the Foreign Corrupt Practices Act after pleading guilty and was sentenced to six months in prison.

  37. 37.

    15 USC s. 78dd-2 (1998).

  38. 38.

    The full formulation by Hellman is “an exchange across boundaries prohibited by the relevant decision-maker” where “an exchange across boundaries” is defined as an exchange of “values … of different types,” such as an “exchange of money for a vote.” Deborah Hellman, “Understanding Bribery”, in Larry Alexander and Kimberly Kessler Ferzan (eds.), The Palgrave Handbook of Applied Ethics and the Criminal Law (Switzerland: Palgrave Macmillan, 2019): pp. 147–148. In the hypothetical being discussed here, a monetary payment is being made in order for a sovereign fund to make a monetary payment to purchase a building, so it is not clear whether this is “an exchange across boundaries” in Hellman’s terms. I will set that complication aside here, given it is clear that the hypothetical describes an instance of bribery, even if the exchange is not “across boundaries.”

  39. 39.

    Kevin Davis, Between Impunity and Imperialism: The Regulation of Transnational Bribery (New York: Oxford University Press, 2019), p. 60.

  40. 40.

    Cf. ibid., pp. 60 and 236 (describing the harm of a bribery scheme in Haiti to consist of “the Haitian government... receiv[ing] less money than it should have” and calling it a form of stealing from ordinary Haitians).

  41. 41.

    I noticed, when I lived in Florence some years ago, that the locals interpreted the “24-h no parking” sign as “free parking” (as in there were no meters to feed) in certain spots, and it was important to know where that was the case and where that was not.

  42. 42.

    Cf. Douglas Husak, “The ‘But-Everyone-Does-That!’ Defense”, Public Affairs Quarterly 10(4) (1996): pp. 307–334.

  43. 43.

    I thank Kimberly Ferzan for raising this question.

  44. 44.

    Criminal Division of the U.S. Department of Justice and the Enforcement Division of the U.S. Securities and Exchange Commission, “A Resource Guide to the U.S. Foreign Corrupt Practices Act” (2d ed., 2020): p. 23.

  45. 45.

    Ibid., p. 24 (“In practice, the local law defense arises infrequently, as the written laws and regulations of countries rarely, if ever, permit corrupt payments.”).

  46. 46.

    Cf. Laura Valentini, “The Natural Duty of Justice in Non-Ideal Circumstances: On the Moral Demands of Institution Building and Reform”, European Journal of Political Theory (2017): pp. 6–12 (considering citizens’ obligations in situations of “moderate expected non-compliance” and “pervasive expected non-compliance”).

  47. 47.

    Laura Valentini, “The Content-Independence of Political Obligation: What It Is and How to Test It”, Legal Theory 23(2) (2018): p. 135.

  48. 48.

    See, e.g., Duff, The Realm of Criminal Law, pp. 127–137, 167–182, 225–231; Youngjae Lee, “Criminalization, Legal Moralism, and Abolition”, University of Toronto Law Journal 70(2) (2020): pp. 209–211; Dan Markel, “Retributive Justice and the Demands of Democratic Citizenship”, Virginia Journal of Criminal Law 1(1) (2012): pp. 14–17 (distinguishing between “dumb but not illiberal” laws, “illiberal” laws, and “spectacularly dumb” laws); Jeffrie G. Murphy, “Marxism and Retribution”, Philosophy & Public Affairs 2 (1973): pp. 217–243.

  49. 49.

    22 USC s. 2778 (2014).

  50. 50.

    22 CFR s. 120.10 (2014).

  51. 51.

    22 CFR s. 120.17 (2019).

  52. 52.

    This description is based on United States v. Roth, 628 F.3d 827 (6th Cir. 2011).

  53. 53.

    This description is based on United States v. Virgil Griffith, 19 Mag 10,987 (S.D.N.Y. 2019).

  54. 54.

    50 USC s. 1701 (1977).

  55. 55.

    Executive Order 13,466, “Continuing Certain Restrictions with Respect to North Korea and North Korea Nationals” (June 26, 2008); Executive Order 13,551, “Blocking Property of Certain Persons with Respect to North Korea” (August 30, 2010); Executive Order 13,570, “Prohibiting Certain Transactions with Respect to North Korea” (April 18, 2011); Executive Order 13,687, “Imposing Additional Sanctions with Respect to North Korea” (January 2, 2015); Executive Order 13,722, “Blocking Property of the Government of North Korea and the Workers’ Party of Korea, and Prohibiting Certain Transactions with Respect to Korea” (March 15, 2016).

  56. 56.

    50 USC s. 1705(a) (2007).

  57. 57.

    50 USC s. 1705(c) (2007).

  58. 58.

    Executive Order 13,810, “Imposing Additional Sanctions With Respect to North Korea” (September 20, 2017).

  59. 59.

    31 CFR s. 510.206 (1980).

  60. 60.

    For a more sustained defense, see Lee, “Punishing Disloyalty? Treason, Espionage, and the Transgression of Political Boundaries”: p. 299.

  61. 61.

    Cf. Cecile Fabre, “The Morality of Treason”, Law and Philosophy 39 (2020): p. 446.

  62. 62.

    Julie Rose O’Sullivan, “Skilling: More Blind Monks Examining the Elephant”, Fordham Urban Law Journal 39(2) (2011): p. 343.

  63. 63.

    One indicator is the legal system’s conflicted stance on the practice of jury nullification, which is recognized as a feature, not a bug, in the system yet is unmentionable through official channels during a trial. See Duncan v. Louisiana, 391 U.S. 145, 187 (Harlan, J., dissenting) (“A jury may, at times, afford a higher justice by refusing to enforce harsh laws.”); United States v. Thomas, 757 F.2d 606, 614 (“We categorically reject the idea that, in a society committed to the rule of law, jury nullification is desirable or that courts may permit it to occur when it is within their authority to prevent.”).

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Thanks to John Hasnas for organizing the conference on proportionality in criminal law where this paper was presented. Thanks also to participants at the conference, including Larry Alexander, Mihailis Diamantis, Kimberly Ferzan, John Hasnas, Craig Lerner, and Gabe Mendlow, for helpful comments, and to Chrystel Yoo and Susu Zhao for research and editorial assistance.

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Lee, Y. Mala Prohibita and Proportionality. Criminal Law, Philosophy 15, 425–446 (2021).

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  • Malum prohibitum
  • Proportionality
  • FCPA
  • Money laundering
  • Export controls