(To read the previous post in this series, click here.)


What may override a presumption of liberty?  Conventions of rhetoric require us to justify public policies by argument and evidence.  Proponents of prohibitions adduce a variety of rationales.  Typically, rationales claim to prevent, reduce, or address ‘bads;’ for example, harm to others, self-harm, inequality, commodification, and slippery slopesCost-benefit analysis takes a broader view and considers also the good or utility from contested behaviors and markets.  In this post, I focus on arguments from ‘harm to others’ (protection of innocent third parties) and from ‘self-harm’ (paternalism).  These rationales have greatest explanatory scope.  I discuss also psychology of prohibition (repugnance and status).  I will consider arguments from inequality, commodification, and slippery slopes in subsequent posts about specific prohibitions.


Harm to others & protection of third parties

John Stuart Mill declares, “the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection.” (On Liberty, 1859)  Interference may take the form of prohibition, regulation, or taxation.


Given that our discussion is about behaviors that don’t intrinsically involve force or fraud, the relevant concern here is indirect harm to others.  Economics has a technical concept, which is related to the commonsense concept of indirect harm: externalities.  Bryan Caplan explains:

“Externalities are probably the argument for government intervention that economists most respect.  Externalities are frequently used to justify the government’s […] prohibition of products with negative externalities. Economically speaking, however, this is overkill. [. …] if laissez-faire provides too much cocaine, a measured response is to tax it, not ban it completely.”


Pollution and congestion are core examples of negative externalitiesCaplan revisits these examples of externalities in a recent interview:

“In terms of the morality of it, it doesn’t make sense to say there is an unlimited right to put out as much poison in the air as you think.  On the other hand, merely breathing, is that an offense?  Well, there’s something in the middle, where you’d say it becomes a violation of the rights of others.  Taxing people to keep them under that seems like a very clean way of doing it.  The logic of it is pretty hard to argue with.  The only thing I’ve heard is the idea, that once you start raising money by taxing bad things, then government will start calling everything bad and persecuting people for no other reason.”  (cue time: 24:15)


Notice that a government behavior (taxation of a negative externality), too, can have a negative side-effect (opportunistic, illiberal expansion of what counts as harm to others).  Prohibitions often have major adverse side-effects; for example, drug prohibition fosters organized crime and corruption of law enforcement.  Regulations, too, can have negative side-effects.  Jeffrey Miron & co-authors make a tentative case that stricter regulation of prescription opioids has backfired by ‘causing’ a substantial fraction of ‘users’ to turn to riskier, illicit or non-prescription substitutes: heroin and fentanyl.  Regulation entails prohibition outside the limits of regulation.


Self-harm & paternalism

Gerald Dworkin defines paternalism as “the interference of a state or an individual with another person, against their will, and defended or motivated by a claim that the person interfered with will be better off or protected from harm.”


However, paternalism can, and often does, make its target worse off and exposed to harm by others.  There are two senses of worse off: deprived and afflicted.  A target of paternalism is deprived if she is denied a liberty, the exercise of which would make her better off.  A ban on markets for kidneys for transplantation makes an absolutely poor person in, say, India worse off by depriving her of an economic opportunity that could lift her (and her family) from poverty.  A target of paternalism is afflicted if she defies the prohibition and incurs harms from illegality.  A person who would sell one of her kidneys in an illicit market incurs greater risks of medical malpractice, force (private coercion), and fraud, as well as new risks of arrest and punishment (public coercion).


Gang of Four—the post-punk band, not the leaders of a faction in the Chinese Cultural Revolution!—voice a plea against paternalistic coercion:

“Save me from the people who would save me from myself.  They got muscle for brain.”—Songs of the Free LP (1982), track A3.


Mill, too, rejects the idea that self-harm justifies paternalism:

“[…] a man’s mode of laying out his own existence is best not because it is the best in itself, but because it is his own mode […].”


Dworkin draws distinctions, which can demarcate a sphere of limited paternalism, consisting in checks to ascertain that a person pursues her own mode in a voluntary, clear-eyed, well-informed way:

“Hard vs. soft paternalism [… .] Soft paternalism is the view that the only conditions under which state paternalism is justified is when it is necessary to determine whether the person being interfered with is acting voluntarily and knowledgeably. […] Weak vs. strong paternalism [… .] we may interfere with mistakes about the facts but not mistakes about values.”


What Dworkin calls ‘soft, weak paternalism’ is essentially a rationale for regulation, rather than full prohibition.


Psychology of Prohibition

Paternalistic prohibitions often are couched as protecting people from choice situations rife with pitfalls of individual rationality.  If I may invent an awkward term of art, the aim is to prevent self-harm that springs from insidious endogenous irrationality.  Core instances are self-defeating behaviors in ‘vice markets’ (drugs, sex, gambling).  A key concept is addiction, which I will discuss in a subsequent blogpost about drug prohibition.  Here I sketch three pitfalls of individual rationality.  Each is characteristic of a specific vice market.  1) Drugs.  There is a pitfall of uncertainty about entry into addiction.  A novice might ensnare himself in the thought, ‘I can experiment with drugs without becoming an addict.’  The belief finds superficial comfort in group statistics; for example, most people who consume cocaine don’t become addicts.  However, some people do become addicts—and an individual might be highly prone to addiction.  Given the limits of current diagnostic technology, can one know before experience if one is prone to cocaine addiction?  Experimentation here involves not risk, but uncertainty (about one’s type).  2) Sex work.  A novice might face a different pitfall of rationality about entry into sex work.  She readily observes that compensation in the sex industry has a peculiar time profile.  Unlike the professions, which require long, costly investment in human-capital formation and in formal credentials, the ‘world’s oldest profession’ rewards natural endowments, youth, and even inexperience.  She might ensnare herself in the thought, ‘my best strategy is part-time sex work, which will enable me to improve my standard of living now, save more for the future, and invest in education for a mainstream career afterwards.’  But would a novice accurately estimate the probability that she will suffer psychological trauma from sex work (trauma that would derail this strategy)?  3) Gambling.  Pitfalls of rationality can occur despite experience.  A ‘problem gambler’ might ensnare himself in the thought, ‘One big win will solve all the problems created by my previous gambling.’  Although a big win can wipe out one’s losses, the belief that a big win ‘will solve all the problems’ probably is fantasy.  Instead, problem gamblers predictably squander a big win (often in more gambling).


Proponents of prohibition, too, are far from immune to psychological mechanisms.  Sheer repugnance, outrage, and bias play massive roles in prohibitions.  Alvin Roth argues that many prohibitions are motivated at least partly by repugnance.  Robert Sugden notes: “Disgust […] is known to be particularly susceptible to emotional contagion.”—The Community of Advantage: A Behavioural Economist’s Defence of the Market (Oxford U. Press, 2018), p. 259.  Bryan Caplan shows that voters broadly exhibit anti-market bias and anti-foreign bias.  In a fascinating study, Robert J. MacCoun reports his findings about outrage from a set of carefully designed surveys:

“Three public opinion studies examined public attitudes toward prevalence reduction (PR; reducing the number of people engaging in an activity) and harm reduction (HR; reducing the harm associated with an activity) across a wide variety of domains. Studies 1 and 2 were telephone surveys of California adults’ views on PR and HR strategies for a wide range of risk domains (heroin, alcoholism, tobacco, skateboarding, teen sex, illegal immigration, air pollution, and fast food). ‘Moral outrage’ items (immoral, disgusting, irresponsible, dangerous) predicted preference for PR over HR, with disgust the most important predictor. In contrast, preferences were not predicted by whether the risk behavior was common, no one else’s business, or harmless. Study 3 explored whether there are domains where liberals might reject HR. A sample of liberal students preferred HR > PR for heroin, but PR > HR for ritual female circumcision; path analysis suggested that this reversal was explained by moral outrage rather than consequentialist judgments of harm to self and harm to others.”


Outrage can interact with innumeracy to focus policy discussion on ‘taking action’ about rare, but atrocious events.  In these contexts, cost-benefit analysis is taboo.  The admixture of outrage and innumeracy then fuels demands for regulation or prohibition, targeting elusive (or extremely costly) zero prevalence.


Psychological mechanisms also shape interactions among plural motivations: interests, passions (including repugnance & bias), impartiality (Reason, justice, the public good), social norms, esteem, and unconscious ‘issues.  Communities have normative hierarchies of motivations.  For example, modern societies often exhibit a norm that the public good should take precedence over other motivations in the public sphere.  The normative hierarchy is either Reason > Passion > Interest; or Reason > Interest > Passion.  However, in any given individual, the various potencies of motivations might deviate from the normative hierarchy. Jean de la Bruyère  observes, “Nothing costs passion less than to place itself above Reason; passion’s great triumph is to beat interest.” (Rien ne coûte moins à la passion que de se mettre au-dessus de la raison: son grand triomphe est de l’emporter sur l’intérêt.)  David Hume observes that most people place interest above Reason: “’tis no less rare to meet with persons who can pardon another any opposition he makes to their interest, however justifiable that opposition may be by the general rules of morality.”  Thus the empirical hierarchy of individual psychology is either Interest > Passion > Reason; or Passion > Interest > Reason.  Adam Smith observes , “Man naturally desires, not only to be loved, but to be lovely; […] He desires not only praise, but praise-worthiness.”  The tension between public and private hierarchies of motivation, and the private desire for public esteem, then often induce persons to camouflage motivations, more or less deliberately, to conform to social expectations.  Moreover, a need for self-esteem can cause a person, unconsciously, to hide her motives from herself (self-deception) or to conform also inwardly to social expectations (transmutation).  A stylized illustration: If a person initially is viscerally opposed to gay marriage, and if there is a convention that repugnance is not acceptable as a public reason, then the person might borrow consonant arguments from the forum—e.g., ‘gay marriage would confound children’—and persuade herself that she is motivated by the public good.


Robin Hanson discerns a different psychology—a psychology of status, prestige, and dominance—when he removes the mask from paternalism:

“we justify paternalism in terms of how it will help A, but actually support paternalism mostly for status reasons: to raise the status of some, lower the status of others, show our support for the high status, and distance ourselves from the low status. Sometimes that happens to help A, and other times it happens to hurt A, but it isn’t fundamentally designed to do either.  Note that paternalism illustrates the complex relation between prestige and dominance, the two subcomponents of status. Freely following someone’s advice would be an affirmation of their prestige, but forcing others to take your advice is an act of dominance. We are apparently often comfortable giving the power of dominance to people who would otherwise be treated as prestigious.”


Ingenious case studies like MacCoun’s notwithstanding, strategic misrepresentation of motivations and psychological opacity make it difficult not only to establish, but also to rule out, that a prohibition is grounded in repugnance (outrage) or status.


Or perhaps I’ve overdrawn the contrast between psychology (whether repugnance or status) and public reason. David Hume, dethroning Reason, writes, “when you pronounce any action or character to be vicious, you mean nothing, but that from the constitution of your nature you have a feeling or sentiment of blame from the contemplation of it.”  Sugden, following Hume, writes, “a sense of morality is a kind of feeling” (p. 258).


My next  post will be about marriage of more than two persons (‘free marriage’).  If you would like background readings, I recommend David Friedman, “Marriage, Sex, and Babies”, and blogposts or short opinion pieces by Bryan Caplan, Stephen Macedo, Richard Posner, and  Alex Tabarrok.