¹ See generally Amna A. Akbar et al., Movement Law, 73 Stan. L. Rev. 821 (2021); Katherine Florey, Toward Tribal Regulatory Sovereignty in the Wake of the COVID-19 Pandemic, 63 Ariz. L. Rev. 399 (2021); Eric E. Johnson & Theodore C. Bailey, Legal Lessons from a Very Fast Problem: COVID-19, 73 Stan. L. Rev. Online 89 (2020); Etienne C. Toussaint, Of American Fragility: Public Rituals, Human Rights, and the End of Invisible Man, 52 Colum. Hum. Rts. L. Rev. 826 (2021); Robyn M. Powell, Applying the Health Justice Framework to Address Health and Health Care Inequities Experienced by People with Disabilities during and after COVID-19, 96 Wash. L. Rev. 93 (2021); Divya Ramjee et al., COVID-19 and Digital Contact Tracing: Regulating the Future of Public Health Surveillance, 2021 Cardozo L. Rev. De-Novo 101 (2021).

² See generally Kelly J. Deere, Governing by Executive Order during the COVID-19 Pandemic: Preliminary Observations Concerning the Proper Balance between Executive Orders and More Formal Rule Making, 86 Mo. L. Rev. 722 (2021); James G. Hodge et al., COVID’S Constitutional Conundrum: Assessing Individual Rights in Public Health Emergencies, Tenn. L. Rev (forthcoming) (providing details on the progress of the pandemic in the US and abroad). For data on current infection rates, see Worldometer, https://www.worldometers.info/coronavirus/ [https://perma.cc/J3LG-L3SA] (last visited Jan. 23, 2022, 12:03 PM).

³ See, e.g., James G. Hodge et al., Legal Challenges Underlying COVID-19 Vaccinations, 49 J. L., Med. & Ethics 495, 497 (2021); Catherine J.K. Sandoval et al., Legal Education During the COVID-19 Pandemic: Put Health, Safety and Equity First, 61 Santa Clara L. Rev. 367, 373 (2021). For a while, there were concerns that the “Delta Variant” may be vaccine-resistant. See Apoorva Mandavilli, Why Vaccinated People Are Getting ‘Breakthrough’ Infections, N.Y. Times (July 22, 2021), https://www.nytimes.com/ 2021/07/22/health/coronavirus-breakthrough-infections-delta.html [https://perma.cc/PG8G-XQP9]. More recently, the “Omicron” variant has been raising similar concerns. See Maggie Fox, Studies Add to Evidence Omicron Sneaks Past Vaccines But May Cause Milder Disease, CNN Health (Dec. 14, 2021, 10:26 PM), https://edition.cnn.com/2021/12/14/health/omicron-variant-south-africa-details/index.html [https://per ma.cc/7ZNS-EET4].

⁴ See generally Ramjee et al., supra note 1; Mason Marks, Drug Regulation for the COVID-19 Mental Health Crisis, 72 Admin. L. Rev. 649 (2020); Eric M. Swalwell & R. Kyle Alagood, Biological Threats Are National Security Risks: Why COVID-19 Should Be a Wake Up Call for Policy Makers, 77 Wash. & Lee L. Rev. Online 217 (2021). As one example, Germany tried imposing a “Lockdown Light”, keeping restaurants and bars open, in November 2020. After this policy insufficiently reduced infections, a “hard lockdown” was adopted in late December 2020. Thereafter, a “Mega Lockdown”—with tougher restrictions—was imposed in January 2021. See, e.g., Vicky McKeever, Why Germany’s Coronavirus Strategy Doesn’t Appear to be Working this Time Around, CNBC (Nov. 6, 2020, 4:38 AM), https://www.cnbc.com/2020/11/06/why-germanys-coronavirus-strategy-doesnt-appear-to-be-working.html [https://perma.cc/ JB8Y-37X6] (discussing why the “lockdown light” failed); Reuters Staff, Germany Heading Towards Extension of Hard Lockdown, Reuters (Jan. 4, 2021, 5:44 AM), https://www.reuters.com/article/us-health-coronavirus-germany-idUSKBN299112 [https://perma.cc/H6UB-ENWZ] (discussing the decision to extend the hard lockdown); Neil Murphy, Merkel Plans Mega-lockdown as Germany Suffers Record Covid Deaths, The National News (Jan. 14, 2021), https://www.thenationalnews.com/world/europe/merkel-plans-mega-lockdown-as-germany-suffers-record-covid-deaths-1.1146435 [https://perma.cc/6WKJ-FVWT] (discussing the mega-lockdown).

⁵ See generally Cary Coglianese & Neysun A. Mahboubi, Administrative Law in a Time of Crisis: Comparing National Responses to COVID-19, 73 Admin. L. Rev. 1 (2021); Hodge, supra note 3; Craig Konnoth, Narrowly Tailoring the COVID-19 Response, 11 Calif. L. Rev. Online 193, 195-97 (2020); Palina Kolvan et al., Pandemic Backsliding: Democracy Nine Months into the COVID-19 Pandemic (V-Dem Institute, Policy Brief No. 26, 2020), http://v-dem.net/pb.html [https://perma.cc/64X9-3UJS].

⁶ See, e.g., Samer Kharroubi & Fatima Saleh, Are Lockdown Measures Effective Against COVID-19?, 8 Frontiers in Pub. Health 1, 1 (2020) (finding that a lockdown in Lebanon was effective); Moritz U.G Kraemer et al., The Effect of Human Mobility and Control Measures on the COVID-19 Epidemic in China, 368 Science 493, 493 (2020) (finding that a lockdown in Wuhan, China, was effective); Eyal Zamir & Doron Teichman, Governmental Decision-Making Regarding the COVID-19 Pandemic—a Behavioral Perspective 1 (Sep. 24, 2020) (unpublished manuscript), https://ssrn.com/abstract=3698682 [https://perma.cc/L6EU-87PR]. For an English-language overview of the regulatory efforts addressed in Zamir & Teichman’s manuscript, see Ruth Levush, Israel: Law Granting Government Special Authorities to Combat Novel Coronavirus Adopted, Libr. of Cong. (July 29, 2020), https://www.loc.gov/item/global-legal-monitor/2020-07-29/israel-law-granting-government-special-authorities-to-combat-novel-coronavirus-adopted [https://perma.cc/GYA5-UQPN].

⁷ See, e.g., John Gibson, Government Mandated Lockdowns Do Not Reduce COVID-19 Deaths: Implications for Evaluating the Stringent New Zealand Response, N.Z. Econ. Papers, Nov. 2020, at 1, 6 (finding empirical evidence of ineffective lockdowns in the US); Joshua Nazareth et al., Early Lessons from a Second COVID-19 Lockdown in Leicester, UK, 396 The Lancet 10245, at e4 (2020) (finding that testing policy in Leicester was ineffective); Rahi Abouk & Babak Heydari, The Immediate Effect of COVID-19 Policies on Social-Distancing Behavior in the United States, 136 Pub. Health Reps. 245, 245 (2021) (finding no effect of four out of six policies analyzed).

⁸ See, e.g., Rosie Perper, As the Coronavirus Spreads, One Study Predicts that Even the Best-Case Scenario is 15 Million Dead and a $2.4 Trillion Hit to Global GDP, Bus. Insider (Mar. 5, 2020, 5:15 AM), https://www.businessinsider.com/coronavirus-death-toll-global-gdp-loss-australian-national-university-study-2020-3 [https://perma.cc/E5DY-MBCV ]; Maria Polyakova et al., Initial Economic Damage from the COVID-19 Pandemic in the United States is more Widespread Across Ages and Geographies than Initial Mortality Impacts, 117 Proc. Nat’l Acad. Scis., 27934, 27937 (2020).

⁹ As of December 2021, the FDA has given a full approval only to a vaccine developed by Pfizer/Biontech and an emergency-use approval for vaccines by Moderna and Johnson & Johnson. See Food & Drug Admin., COVID-19 Vaccines, https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/covid-19-vaccines [https://perma.cc/T4TZ-N6K5] (last visited Dec. 27, 2021). For a discussion of the clinical trials, see Ana Santos Rutschman, Vaccine Clinical Trials and Data Infrastructure, 2021 Utah L. Rev. 771 (2021). In December 2021, a first treatment for COVID-19 was also given emergency-use approval by the FDA. See Food & Drug Admin, Coronavirus (COVID-19) Update: FDA Authorizes First Oral Antiviral for Treatment of COVID-19, https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-first-oral-antiviral-treatment-covid-19 [https://perma.cc/57RQ-VSAY] (last visited on Dec, 27, 2021).

¹⁰ For recent evidence on public support of different COVID-19 mitigation strategies, see generally Jerg Gutmann, Roee Sarel & Stefan Voigt, Measuring Constitutional Loyalty: Evidence from the COVID-19 Pandemic (unpublished manuscript) (Feb. 4, 2022), https://ssrn.com/abstract=4026007.

¹¹ We use the term “mitigation strategies” (or “mitigation policies”) to describe any type of measure taken to slow down the virus. Note that in some existing studies, the term is used to describe a specific type of policy that is aimed to manage but not eradicate the virus. See, e.g., Stefan Baral et al., Leveraging Epidemiological Principles to Evaluate Sweden’s COVID-19 Response, 54 Annals Epidemiology 21, 23 (2021) (“The mitigation-based approach in Sweden appeared to limit the breadth of health disruption facilitating the overall health and wellbeing of Swedes.”).

¹² Kraemer et al., supra note 6, at 493.

¹³ Alexander Chudik et al., Mandated and Targeted Social Isolation Policies Flatten the COVID19 Curve and Can Help Mitigate the Associated Employment Losses, VoxEU (May 2, 2020), https://voxeu.org/article/mandated-targeted-social-isolation-can-flatten-covid-19-curve-and-mitigate-employment-losses [https://perma.cc/YLY9-8GVK].

¹⁴ Malouke Esra Kuiper et al., The Intelligent Lockdown: Compliance with COVID-19 Mitigation Measures in the Netherlands 2 (Amsterdam Law School Research Paper No. 2020-20, 2020).

¹⁵ Moran Bodas & Kobi Peleg, Self-Isolation Compliance in the COVID-19 Era Influenced by Compensation: Findings from a Recent Survey in Israel: Public Attitudes Toward the COVID-19 Outbreak and Self-isolation: A Cross Sectional Study of the Adult Population of Israel, 39 Health Aff. 936, 939 (2020).

¹⁶ Peter D. Lunn et al., Motivating Social Distancing During the COVID-19 Pandemic: An Online Experiment, 265 Soc. Sci. & Med. (Special Issue) 1, 1 (2020).

¹⁷ Benjamin van Rooij et al., Compliance with COVID-19 Mitigation Measures in the United States 1 (Amsterdam Law School Research Paper No. 2020-21, 2020).

¹⁸ Cory Clark et al., Predictors of COVID-19 Voluntary Compliance Behaviors: An International Investigation, 2 Glob. Transitions 76, 76-77 (2020).

¹⁹ Craig A. Harper et al., Functional Fear Predicts Public Health Compliance in the COVID-19 Pandemic, 19 Int’l J. Mental Health & Addiction 1875, 1877 (2020).

²⁰ Amy Nivette et al., Non-compliance with COVID-19-related Public Health Measures Among Young Adults in Switzerland: Insights from a Longitudinal Cohort Study, Soc. Sci. & Med. (2021) 1, 7, 8.

²¹ Joseph F. Francois & H. Keith Hall, Partial Equilibrium Modeling, in Applied Methods for Trade Policy Analysis: A Handbook 6 (Joseph F. Francois & Kenneth A. Reinert eds., 1997).

²² See infra Part II. A for a discussion of partial vs. general equilibria.

²³ This example is for illustration purposes only. We are, of course, well aware that COVID-19 generally leads to unemployment in most sectors.

²⁴ See, e.g., Robert Cooter & Thomas Ulen, Law and economics 38 (6th ed., 2016) (defining a general equilibrium as “conditions under which the independent decisions of utility-maximizing consumers and profit-maximizing firms will lead to the inevitable, spontaneous establishment of equilibrium in all markets simultaneously”).

²⁵ As one recent example that utilizes a similar view as the one we adopt in this paper, see generally Lukasz Rachel, An Analytical Model of COVID-19 Lockdowns (Dec. 4, 2020) (on file with author), https://sites.google.com/site/lukaszrachel/home [https://perma.cc/Q3GD-GVP4].

²⁶ See, e.g., Marcus R. Keogh-Brown et al, The Impact of COVID-19, Associated Behaviours and Policies on the UK Economy: A Computable General Equilibrium Model, 12 SSM-Population Health 100666, 100666 (2020) (constructing a general equilibrium model to predict the economic impacts on COVID-19 on the UK economy).

²⁷ In economics, two goods are considered substitutes if an increase in the price of one good leads to an increase in the demand for the other good. This happens when both goods serve a similar need (e.g. Pepsi and Coca Cola). Conversely, two goods are considered complements if the increase in the price of one good leads to a decrease in the demand for the other good. This happens when both goods provide more value when consumed together. See, e.g., Neal Katyal, Kumar, Deterrence’s Difficulty, 95 Mich. L. Rev. 2385, 2386 (1997); Cooter & Ulen, supra note 24, at 184.

²⁸ See, e.g., Sangho Kim, Cinema Demand in Korea, 22 J. Media Econ. 36, 51 (2009) (“cinema is a substitute for trips to cultural facilities“). But see, Louis Lévy Garboua & Claude Montmarquette, A Microeconometric Study of Theatre Demand, 20 J. Cultural Econ. 25, 40 (1996) (arguing that cinemas are a substitute only beyond a certain threshold of cinema-going).

²⁹ Of course, it is also possible that cinema is a substitute for restaurant if one has a limited budget that is sufficient for only one outdoor activity.

³⁰ See generally Jeremy I. Bulow et al., Multimarket Oligopoly: Strategic Substitutes and Complements, 93 J. Pol. Econ. 488 (1985) (originally coining the terms “strategic substitutes” and “strategic complements” in the context of production); Zhigang Cao et al., Embedding Games with Strategic Complements into Games with Strategic Substitutes, 78 J. Math. Econ. 45 (2018). For examples related to legal policies, see, e.g., Nuno Garoupa, A Note on Private Enforcement and Type-I Error, 17 Int’l Rev. L. & Econ. 423, 425 (1997) (“Increasing accuracy is a way of increasing deterrence. Thus, expenditures on accuracy and on detection are strategic substitutes.”); Matthew C. Stephenson, The Strategic Substitution Effect: Textual Plausibility, Procedural Formality, and Judicial Review of Agency Statutory Interpretations, 120 Harv. L. Rev. 528 (2006); Oren Bar-Gill & Omri Ben-Shahar, The Uneasy Case for Comparative Negligence, 5 Am. L. & Econ. Rev. 433, 447 (2003) (“Here, it is plausible that when one party reduces its care the marginal productivity of the other party’s care increases, making the parties’ care levels “strategic substitutes.”).

³¹ We use the terms complementarity and synergy synonymously.

³² For concrete examples, see infra Part III.

³³ In addition, the economic effects of the pandemic might also differ from country to country. See, e.g., Asger Lau Andersen et al., Pandemic, Shutdown and Consumer Spending: Lessons from Scandinavian Policy Responses to COVID-19 (May 10, 2020) (unpublished manuscript), https://arxiv.org/abs/2005.04630 [https://perma.cc/3PV6-LPDV] (comparing Denmark and Sweden); Austan Goolsbee & Chad Syverson, Fear, Lockdown, and Diversion: Comparing Drivers of Pandemic Economic Decline 2020, 193 J. Pub. Econ., Jan. 2021, 1-2.; see also Doron Teichman & Kristen Underhill, Infected by Bias: Behavioral Science and the Legal Response to COVID-19, 47 Am. J. L. & Med. 205 (2021)).

³⁴ For instance, COVID-19 mitigation strategies may be difficult to implement due to coordination problems between countries or because of political constraints, such as the politician’s need to raise public support for the policy. See Zamir & Teichman, supra note 6, at 207; Levush, supra note 6; see generally Eyal Benvenisti, The WHO—Destined to Fail?: Political Cooperation and the COVID-19 Pandemic, 114 Am. J. Int’l L. 588 (2020).

³⁵ See generally Richard Craswell, Passing on the Costs of Legal Rules: Efficiency and Distribution in Buyer-seller Relationship, 43 Stan. L. Rev. 361, 361 (1991).

³⁶ See, e.g., Cooter & Ulen, supra note 24, at 28-33.

³⁷ For instance, if widget is a basic good, consumers will continue to buy it even if the price increases. However, they will then have less available income for other goods, leading to a reduction in demand for those goods.

³⁸ See generally John Fender, A General Equilibrium Model of Crime and Punishment, 39 J. Econ. Behav. & Org. 437, passim (1999) (developing a model of criminal behavior); James B. Kau et al., A General Equilibrium Model of Congressional Voting, 97 Q. J. Econ. 271, passim (1982) (developing a model for congressional voting). However, it has been argued that also law and economics insufficiently accounts for general equilibrium effects. See Henry E. Smith, Law and Economics: Realism or Democracy, 32 Harv. J. L. & Pub. Pol’y 127, 133 (2009) (“Partial equilibrium and general equilibrium are two very different things. Law and economics rarely rests on a general equilibrium analysis. But partial analyses must be taken with a grain of salt; it is characteristic of complex systems that a subpart may not share properties with the whole.”).

³⁹ See, e.g., Jeffrey L Dunoff & Joel P. Trachtman, The Law and Economics of Humanitarian Law Violations in Internal Conflict, 93 Am. J. Int’l L. 394, 400 (1999) (“Price theory assumes that each individual engages in a rational cost-benefit analysis, and suggests that it is necessary to make the price of noncompliance high enough to exceed the perceived benefits from noncompliance.”); Anja Weber & Erik Maier, Reducing Competitive Research Shopping with Cross-channel Delivery, 24 Int’l J. Elec. Com. 78, 79 (2020) (“A cost-benefit analysis drives consumers’ channel choice, in that consumers will choose the channel with the highest utility for their given purchase goal”).

⁴⁰ Driving may, of course, entail other costs (e.g. the risk of causing an accident) and its benefit depends also on substitutes and complements. As one example, a recent study finds that an increase in the price of children car seats (which is a complement to cars) is an implicit cost of buying a car. See generally Jordan Nickerson & David H. Solomon, Car Seats as Contraception (Sept. 22, 2020) (unpublished manuscript), https://ssrn.com/abstract=3665046 [https://perma.cc/Y4SX-GDD5].

⁴¹ As one example, the cost of a children’s car seat might not only affects driving, but also the ex-ante decision of how many children to have. Id.

⁴² This result, that a competitive equilibrium is efficient, is known as the “first fundamental theorem of welfare economics.” See, e.g., id.; Matthew Dimick, The Law and Economics of Redistribution, 15 Ann. Rev. L. & Soc. Sci. 559, 582 (2019)).

⁴³ Market frictions here refer to two types of problems: asymmetric information (e.g. where sellers or buyers do not have full information about the value of a product) and externalities (where a product sold has a positive or negative effect on others who are neither the sellers nor the buyers). See, e.g., Joseph T. Mahoney & Lihong Qian, Market Frictions as Building Blocks of an Organizational Economics Approach to Strategic Management, 34 Strategic Mgmt. J. 1019, 1021 (2013) (listing frictions, including externalities); Hiba Hafiz, Structural Labor Rights, 119 Mich. L. Rev. 651, 693 (2021) (mentioning information asymmetry as a market frictions).

⁴⁴ Dimick, supra note 42.

⁴⁵ Note that economists mostly focus on social welfare in the form of Kaldor-Hicks efficiency—which assumes that the goal is to maximize the sum of utilities of individuals, irrespective of the distribution. See Cooter & Ulen, supra note 24, at 42. Thus, legal interventions that aim to promote fairness or justice considerations would only be relevant if one adopts a non-efficiency perspective.

⁴⁶ See, e.g., Allan Gibbard, Social Choice Theory and the Imperfectability of a Legal Order, 10 Hofstra L. Rev. 401, 402 (1982); Adrian Vermeule, The Invisible Hand in Legal and Political Theory, 96 Va. L. Rev. 1417, 1418-19 (2010).

⁴⁷ Externalities occur when benefits or costs of certain actions have an effect on third parties. For instance, a seller and a buyer may achieve a mutually agreeable transaction surrounding the sale of a polluting product, but such purchases also have negative effects (negative externalities) on others who are not part of the negotiations. See, e.g., Cooter & Ulen , supra note 24, at 39-40.

⁴⁸ See, e.g., Nicholas W. Papageorge et al., Socio-demographic Factors Associated with Self-protecting Behavior During the Covid-19 Pandemic, 34 J. Population Econ. 691 (2021) (“The spread of illness is largely influenced by human behavior. In the presence of strong externalities, a concern is that individual behavior may not align with socially optimal outcomes”); Teichman & Underhill, supra note 33, at 207 (“when peoples’ choices generate massive negative externalities—as is the case with a highly contagious and deadly virus”).

⁴⁹ See generally: Ricky V. Tso & Benjamin J. Cowling, Importance of Face Masks for COVID-19: A Call for Effective Public Education, 71 Clinical Infectious Diseases 2195 (2020); Christiane Matuschek et al., Face Masks: Benefits and Risks during the COVID-19 Crisis, 25 Eur. J. Med. Res. 1 (2020).

⁵⁰ See, e.g., Reuters Staff, Beijing Drug Store Fined $434,530 for Hiking Price of Masks, Reuters (Jan. 29, 2020), https://www.reuters.com/article/china-health-masks-idUSL4N29Y09B [https://perma.cc/H4P3-UJGD] (reporting on an incident in Beijing where a store starkly raised the price of masks in the early days of COVID-19).

⁵¹ For a general discussion on the rational use of facial masks, see generally Shou Feng et al., Rational Use of Face Masks in the COVID-19 Pandemic, 8 Lancet Respiratory Med. 434 (2020); Steve G. Parsons, Is a Requirement to Wear a Mask Economically Valid During COVID-19?, 6 U. Bologna L. Rev. 76 (2021).

⁵² Cooter & Ulen , supra note 24, at 38-42.

⁵³ See, e.g., Shawn HE Harmon & Aisling McMahon, Banking (on) the Brain: From Consent to Authorisation and the Transformative Potential of Solidarity, 22 Med. l. Rev. 572, 576 (2014) (“health is a global public good”); see also Ohan A. Oldekop et al., COVID-19 and the Case for Global Development, World Dev., June 2020, at 1-2.

⁵⁴ For a definition of a public good, see Cooter & Ulen , supra note 24, at 40.

⁵⁵ From a game-theoretical perspective, the problem is one of dominant strategies, where people think that “if everyone else wears a mask, there is no need for me to where a mask” whereas if no one wears a mask then “it will anyway not matter if I am the only one who wears a mask”. Hence, it is a dominant strategy not to wear a mask. See, e.g., Cooter & Ulen, supra note 24, at 35 (discussing dominant strategies).

⁵⁶ Cooter & Ulen , supra note 24, at 40.

⁵⁷ For instance, such a policy was implemented in Israel. TOI Staff, Rules of Israel’s Third Lockdown: What You Need to Know, Times of Israel (Dec. 25, 2020), https://www.timesofisrael.com/israels-third-lockdown-what-you-need-to-know [https://perma.cc/8L8M-MY8G]. Formally, the rule does not prohibit the stay per se, but prohibits going out of ones’ home for the purpose of staying at another person’s home. Id.

⁵⁸ Gary S. Becker, Crime and Punishment: An Economic Approach, 76 J. Pol. Econ. 169 (1968). For a recent discussion of Becker’s framework in the context of pandemics, see Roee Sarel, Crime and Punishment in Times of Pandemics, Eur. J. L. & Econ., Dec. 2021, at 3.

⁵⁹ For simplicity, we assume here that individuals are also risk-neutral.

⁶⁰ The zero on the right-hand side of the inequality is the utility from sitting idly in this example.

⁶¹ In economics, an expected payoff means the product of the probability times the size of the payoff.

⁶² We use the terms “expected penalty” and “expected sanction” synonymously to describe the product of (1) the probability of apprehension and conviction and (2) the size of the sanction. Cooter & Ulen, supra note 24, at 465. Note that some articles consider uncertain sanction sizes, in which case the term is sometimes used separately from the probability of apprehension. See, e.g., Marisa Nack, The Next Step: The Future of New York State’s Human Trafficking Law, 18 J. L. & Pol’y 817, 851 (2010) (“… perpetrators will only engage in trafficking if the benefits of committing the crime outweigh the costs (the probability of detection and the expected sanction)”).

⁶³ See Cooter & Ulen, supra note 24, at 45-46.

⁶⁴ A full consideration of a general equilibrium may also require to account for how different agents, such as law enforcement, victims, and judges. For economic models that incorporate such agents, see generally William J. Furlong, A General Equilibrium Model Of Crime Commission and Prevention, 34. J. Pub. Econ. 87 (1987); Bruce L. Benson et al, Estimating Deterrence Effects: A Public Choice Perspective on the Economics of Crime Literature, 61 S. Econ. J 161 (1994) (developing a model where deterrence depends on police effort)). For example, the effort of police officers may be lower if they sympathize with the victim’s difficulty to avoid social distancing. However, we restrict attention to substitution and complementarity effects.

⁶⁵ Policymakers can influence the expected sanction by either changing the probability of apprehension (e.g. by hiring more police officers) or by changing the penalty (e.g. increasing the monetary fine).

⁶⁶ In economic terms, the problem can also be framed in terms of “opportunity cost”—the cost of foregoing other opportunities. See, e.g., Cooter & Ulen, supra note 24, at 30.

⁶⁷ The term “interaction effect” is often used in econometrics to describe a situation where the joint occurrence of two events causes an effect above and beyond the effect of each event individually. Hence, when there is an interaction effect between “X1” and “X2”, then the effect of X1 on some outcome Y depends on X2. For instance, in the equation $ Y={x}_1+{x}_2+{x}_1\ast {x}_2 $ the effect of increasing $ {x}_1 $ by 1 unit depends on how high $ {x}_2 $ is, due to the last term which is a product of $ {x}_1 $ and $ {x}_2 $ . See, e.g., James H. Stock & Mark W. Watson, Introduction to econometrics 277-278 (2015).

⁶⁸ See Katyal, supra note 27, at 2386.

⁶⁹ These effects are typically known in economics as cross-price elasticities, reflecting what happens to the quantity demanded of product A when the price of product B changes. See, e.g., Terry M. Schlade, Proposed Objective Relevant Product Market Criteria Under Section 2 of the Sherman Act and Section 7 of the Clayton Act, 35 U. Cin. L. Rev. 376, 381 (1966). Substitutes have a positive cross-price elasticity because if the price of a substitute product B becomes more expensive then consumers will demand more of A. Similarly, complements have a negative cross-price elasticity.

⁷⁰ Of course, it is also possible that the meeting’s location will switch to an open-air location, where the risk of infection is lower. However, this is less likely to occur if public gatherings are prohibited as well (whereas business meetings are still allowed and the risk of being detected when conducting private meetings at the office is low).

⁷¹ For a discussion of substitution effects and harmful (criminal) behaviors, see generally Tracey L. Meares et al., Updating the Study of Punishment, 56 Stan. L. Rev. 1171, 1173-74 (2003); Joel Van der Weele, Beyond the State of Nature: Introducing Social Interactions in the Economic Model of Crime, 8 Rev. L & Econ. 401, 413 (2012). The substitution effects are closely related to the concept of “marginal deterrence.” See, e.g., George J. Stigler, The Optimum Enforcement of Laws, 78 J. Pol. Econ. 526, 527 (1970)).

⁷² See Richard A. Posner, An Economic Theory of the Criminal Law, 85 Colum. L. Rev. 1193, 1207 (1985); C.Y. Cyrus Chu & Neville Jiang, Are Fines More Efficient Than Imprisonment?, 51 J. Pub. Econ. 391, 392, 392 n.3 (1993); see also Steven Shavell, A Note on Optimal Deterrence when Individuals Choose among Harmful Acts 1 (Nat’l Bureau of Econ. Research., Working Paper 3061, 1989).

⁷³ For instance, a change in the penalty on drug consumption might lead offenders to either increase their consumption of the same drug, as this becomes less costly on the margins, or switch to another, worse, drug. See Katyal, supra note 27, at 2391, 2400.

⁷⁴ John E. Eck, The Threat of Crime Displacement, 25 Crim. J. Abstracts 527, 527 (1993).

⁷⁵ However, the empirical evidence seems to suggest that displacement is not inevitable and that enforcement may lead to diffusion benefits instead in many cases. See generally Shane D. Johnson et al., Crime Displacement: What We Know, What We Don’t Know, and What It Means for Crime Reduction, 10 J. Experimental Criminology 549 (2014); Rob T. Guerette & Kate J. Bowers, Assessing the Extent of Crime Displacement and Diffusion of Benefits: A Review of Situational Crime Prevention Evaluations, 47 Criminology 1331 (2009).

⁷⁶ See generally Richard Matzopoulos et al., South Africa’s COVID-19 Alcohol Sales Ban: The Potential for Better Policy-Making, 9 Int’l J. Health Pol’y & Mgmt. 486, 486-87 (2020) (discussing a ban in South Africa); Swarndeep Singh et al., The Impact of Nationwide Alcohol Ban during the COVID‐19 Lockdown on Alcohol use‐related Internet Searches and Behaviour in India: An Infodemiology Study, 40 Drug & Alcohol Rev. 196, 196-97 (2021) (discussing a ban in India); City of Hamburg, Corona Rules and Regulations in Hamburg, §4d (Dec. 23, 2020), https://www.hamburg.com/residents/settle/health/13921528/r ules-and-regulations/ [https://perma.cc/FWJ8-AF9F] (enacting a ban on public consumption of alcohol in Hamburg, Germany.)

⁷⁷ For example, if meeting friends without drinking yields a utility of “4.5,” then the alcohol ban would simply cause people to meet without drinking alcohol, as this would still be larger than the utility of staying home (of “4”).

⁷⁸ See, e.g., Frank J. Chaloupka & Adit Laixuthai, Do Youths Substitute Alcohol and Marijuana? Some Econometric Evidence, 23 E. Econ. J. 253, 253 (1997) (finding evidence that prohibition of drugs leads youth to switch to alcohol).

⁷⁹ See, e.g., Sharmila Devi, Travel Restrictions Hampering COVID-19 Response, 395 Lancet 1331, 1331 (2020); Kevin Linka et al., Is it Safe to Lift COVID-19 Travel Bans? The Newfoundland Story, 66 Computational Mech. 1081, 1081-82 (2020).

⁸⁰ There might be other motivations to restrict flights that are not purely efficiency-driven, such as exploiting the pandemic to prevent the entry of foreigners.

⁸¹ A similar problem arises in the field of marketing, where advertisements for one good may impact the demand for many other goods, leading to a multitude of effects. See Allan D. Shocker, Product Complements and Substitutes in the Real World: The Relevance of “Other Products”, 68 J. Mktg. 28, 28 (2004).

⁸² Katyal, supra note 27, at 2470.

⁸³ For instance, Katyal (id, at 2491) uses the term “Y-optimality” to describe how reductions in other activities can sometimes help prevent other crimes. Id. at 2419. This is similar to our argument of complementarity effects between the prohibition of alcohol consumption in public and the reduction of social gatherings.

⁸⁴ See supra Part III.

⁸⁵ Our first and third example include the effects of social norms and the weather respectively. A recent study found that high social capital and bad weather both reduce movement during COVID-19. Francesca Borgonovi & Elodie Andrieu, Bowling Together by Bowling Alone: Social Capital and Covid-19, Soc. Sci. & Med., Nov. 2020, at 2.

⁸⁶ For a discussion of how social norms may matter during the COVID-19 pandemic in another context (of risk perception), see Teichman & Underhill, supra note 33, at 239-43.

⁸⁷ See, e.g., Christine Jolls et al., A Behavioral Approach to Law and Economics, 50 Stan. L. Rev. 1471, 1476 (1998).

⁸⁸ Gary Charness & Matthew Rabin, Understanding Social Preferences with Simple Tests, 117 Q. J. Econ. 817, 817 (2002).

⁸⁹ See, e.g., Jana Bellová, Behavioural Economics and its Implications on Regulatory Law, 15 Int’l & Comp. L. Rev. 89, 92 (2015); Colin Camerer et al., Regulation for Conservatives: Behavioral Economics and the Case for “Asymmetric Paternalism", 151 U. Pa. L. Rev. 1211, 1216 (2003).

⁹⁰ Lilach Sagiv & Shalom H. Schwartz, Value Priorities and Readiness for Out-group Social Contact, 69 J. Personality & Soc. Psychol. 437, 438 (1995).

⁹¹ Shalom H. Schwartz, Universals in the Content and Structure of Values: Theoretical Advances and Empirical Tests in Twenty Countries, 25 Advances Experimental Soc. Psychol. 1, 11 (1992).

⁹² The social norm we consider here can also be described as “social capital.” See generally Borgonovi & Andrieu, supra note 85.

⁹³ See Andriy Boytsun, Social Norms, Social Cohesion, and Corporate Governance, 19 Corp. Governance: Int’l Rev. 41, 41 (2011).

⁹⁴ Such norms are particularly strong in Mediterranean countries. See, e.g., Howard Litwin, Social Networks and Well-being: A Comparison of Older People in Mediterranean and non-Mediterranean Countries, 65 J. Gerontology Series B: Psychol. Sci. & Soc. Sci. 599, 599 (2010) (finding differences in family networks of the elderly between Mediterranean and non-Mediterranean countries).

⁹⁵ Such an effect has been observed in Israel, where the desire to protect family members seems to have been a strong motivation for complying with lockdowns. See Arielle Kaim et al., Factors that Enhance or Impede Compliance of the Public with Governmental Regulation of Lockdown during COVID-19 in Israel, Int’l J. Disaster Risk Reduction, Sept. 2021, at 5.

⁹⁶ The concept of “crowding-out of intrinsic motivation” is originally attributed to a study of fines imposed for being late to day cares in Israel. See Uri Gneezy & Aldo Rustichini, A Fine is a Price, 29 J. Legal Stud. 1, 16 (2000) (finding the effect can be explained by the fact that people view the fine as a price). In our example, that might also happen, but we are considering a more explicit change by eliminating the incentive to act pro-socially due to the prohibition to meet one’s family.

⁹⁷ This effect would then be the mirror image of the empirical finding that close communities are more careful not to infect one another. Borgonovi & Andrieu, supra note 85, at 22.

⁹⁸ See Regulation of Special Authorities to Handle the New Coronavirus (Emergency Regulation) (tightening of restrictions) (2020), [in Hebrew], https://www.nevo.co.il/law_word/law01/502_363.doc [https://perma.cc/FXM4-VPZZ] (stating that “no person shall leave their place of residence or location of permanent stay …to the public sphere unless it is for one of the following actions or goals […] (16) leaving to a distance of up to 1,000 meters from the place of residence, given that the departure is not in order to stay at another person’s home”); see also Levush, supra note 6 (English overview of the regulations). This regulation is formally temporary but has been extended repeatedly (as of December 2021, it is still in force).

⁹⁹ See generally Yoshinobu Zasu, Sanctions by Social Norms and the Law: Substitutes or Complements?, 36 J. Legal Stud. 379, 379 (2007).

¹⁰⁰ This distinction is typically made by anthropologists. See Pertii J. Pelto, The Differences Between “Tight” and “Loose” Societies, 5 Trans-action 37, 37 (1968).

¹⁰¹ Id.

¹⁰² Michele J. Gelfand et al., Differences Between Tight and Loose Cultures: A 33-nation Study, 332 Science 1100, 1100 (2011).

¹⁰³ Michele J. Gelfand et al., The Relationship between Cultural Tightness–looseness and COVID-19 Cases and Deaths: A Global Analysis, 5 Lancet Planetary Health e135, e142 (2021).

¹⁰⁴ Id.

¹⁰⁵ Jay J. van Bavel et al., Using Social and Behavioural Science to Support COVID-19 Pandemic Response, 4 Nature Hum. Behav. 460, 463 (2020).

¹⁰⁶ Bo Yan et al., Why do Countries Respond Differently to COVID-19? A Comparative Study of Sweden, China, France, and Japan, 50 Am. Rev. Pub. Admin. 762, 762 (2020).

¹⁰⁷ See generally Dimitrios Paraskevis et al., A Review of the Impact of Weather and Climate Variables to COVID-19: In the Absence of Public Health Measures High Temperatures Cannot Probably Mitigate Outbreaks, Sci. Total Env’t, Dec. 2020, at 1-2.

¹⁰⁸ See, e.g., Borgonovi & Andrieu, supra note 85, at 2 (“when weather conditions are poor, leaving home becomes less enjoyable and thus the opportunity cost of staying home decreases”).

¹⁰⁹ Ramadhan Tosepu et al., Correlation between Weather and Covid-19 Pandemic in Jakarta, Indonesia, Sci. Total Env’t ( 2020) 1, 2.

¹¹⁰ Mehmet şahin, Impact of Weather on COVID-19 Pandemic in Turkey, Sci. Total Env’t (2020) 1, 5.

¹¹¹ Note that the type of population who lives in buildings without a garden may be the poorer population in some regions (as the poor cannot afford to live in a house with a garden) but the richer population in other regions (whenever the rich prefer living in luxury towers).

¹¹² See, e.g., Turki M. Habeebullah et al., Impact of Outdoor and Indoor Meteorological Conditions on the COVID-19 Transmission in the Western Region of Saudi Arabia, 288 J. Env’t Mgmt (2021) 1, 1.

¹¹³ Note that the tendency of COVID-19 to spread indoors may also depend on the weather. Id.

¹¹⁴ For instance, Israel imposed three lockdowns. See TOI Staff, Virus Czar: With COVID-19 Mutations, Third Lockdown may not be Israel’s Last, Times Isr. (Jan. 25, 2021, 5:20PM), https://www.timesofisrael.com/virus-czar-with-covid-19-mutations-third-lockdown-may-not-be-israels-last/ [https://perma.cc/Q7JU-3EJP]; Jason Gewirtz, Israel to Enter Third National Lockdown Despite Successful Covid Vaccination Campaign, CNBC (Jan. 5, 2021, 3:46PM), https://www.cnbc.com/2021/01/05/israel-to-enter-third-national-lockdown-despite-successful-covid-vaccination-campaign.html [https://perma.cc/H2YW-8LNC]; see also Teichman & Zamir, supra note 6, at 4. Germany declared a lockdown in November 2020 and extended it several times. See McKeever, supra note 4; Reuters Staff, supra note 4; Murphy, supra note 4.

¹¹⁵ The empirical evidence on whether lockdowns lead to more loneliness is, however, mixed. Some studies find that loneliness is unaffected by the lockdown, whereas others do find an effect—as well as a negative impact of the lockdown on mental health. See, e.g., Martina Luchetti et al, The Trajectory of Loneliness in Response to COVID-19, 75 Am. Psychol. 897, 897 (2020); see generally Maria Elizabeth Loades et al., Rapid Systematic Review: The Impact of Social Isolation and Loneliness on the Mental Health of Children and Adolescents in the Context of COVID-19, 59 J. Am. Acad. Child & Adolescent Psychiatry 1218, 1218 (2020).

¹¹⁶ For simplicity, we neglect here the possibly countervailing behavioral effect known as “moral identity,” where compliance strengthens one’s self-esteem and belief that one is “the good guy,” making it more likely to comply again in the future. See generally Ernesto Dal Bó & Marko Terviö, Self-esteem, Moral Capital, and Wrongdoing, 11 J. Eur. Econ. Ass’n 599, 599 (2013).

¹¹⁷ In game-theory, dynamic games (with more than one time period) are solved using “backward induction”—solving from end to start. See, e.g., Jack Knight & Lee Epstein, On the Struggle for Judicial Supremacy, 30 L. & Soc. Rev. 87, 107 (1996). However, in our simple example, there is no need for complex calculations, as the punishments for violations in the second lockdown have no effect on the decision in the first lockdown.

¹¹⁸ This is simply an implementation of the formula $ b> pf $ that was mentioned in Part II.B. supra.

¹¹⁹ See generally David A. Dana, Rethinking the Puzzle of Escalating Penalties for Repeat Offenders, 110 Yale L.J. 733, 733 (2001); Winand Emons, Escalating Penalties for Repeat Offenders, 27 Int’l Rev. L. & Econ. 170, 170 (2007); Thomas J. Miceli, Escalating Penalties for Repeat Offenders: Why are they so Hard to Explain?, 169 J. Inst. & Theoretical Econ. 587 (2013); Shmuel Leshem & Avraham D. Tabbach, The Option Value of Record-Based Sanctions (Jan. 27, 2020) (unpublished manuscript), https://ssrn.com/abstract=3514094 [https://perma.cc/8E39-RDL4].

¹²⁰ For other examples of how general equilibrium effects relate to complements and substitutes in public policymaking, see generally Dirk Krueger & Alexander Ludwig, On the Optimal Provision of Social Insurance: Progressive Taxation versus Education Subsidies in General Equilibrium, 77 J. Monetary Econ. 72 (2016); Don Fullerton & Garth Heutel, The General Equilibrium Incidence of Environmental Taxes, 91 J. Pub. Econ. 571 (2007).

¹²¹ Gary S. Becker, The Economic Approach to Human Behavior 111 (1976).

¹²² For a discussion of behavioral law and economics in the context of COVID-19, see generally Teichman & Underhill, supra note 33. For a general overview of behavioral law and economics, see, e.g., Doron Teichman & Eyal Zamir, Behavioral Law and Economics 19 (2018).

¹²³ See, e.g., Sabine Frerichs, False Promises? A Sociological Critique of the Behavioural Turn in Law and Economics, 34 J. Consumer Pol’y 289, 289 (2011) (“with the behavioural turn in law and economics, homo oeconomicus seems to be transformed into Homer Economicus, and consumer law prone to be Simpsonized.”).

¹²⁴ See Teichman & Underhill, supra note 33, at 212; see generally Amos Tversky & Daniel Kahneman, Judgment under Uncertainty: Heuristics and Biases, 185 Science 1124 (1974).

¹²⁵ For example, it has been argued that individuals might miscalculate the probabilities of being infected (or of infecting), which might translate into misguided choices. See Zamir & Teichman, supra note 6, at 7; see also Teichman & Underhill, supra note 33, at 212-13 (mentioning examples such as omission bias).

¹²⁶ See Richard H. Thaler & Cass R. Sunstein, Nudge: Improving Decisions About Health, Wealth, and Happiness (rev. ed. 2009); Cass R. Sunstein, Nudges.Gov: Behaviorally Informed Regulation, in The Oxford Handbook of Behavioral Economics and the Law (Eyal Zamir & Doron Teichman eds., 2014).

¹²⁷ See, e.g., Catherine Doherty & Karen Dooley, Responsibilising Parents: The Nudge Towards Shadow Tutoring, 39 Brit. J. Soc. Educ. 551, 556-7 (2017); Thaler & Sunstein , supra note 126 at 6.

¹²⁸ See Teichman & Underhill, supra note 33, at 244.

¹²⁹ Hengchen Dai et al., Behavioural Nudges Increase COVID-19 Vaccinations, 597 Nature 404, 404 (2021).

¹³⁰ Id.

¹³¹ Teichman & Underhill, supra note 33, at 234.

¹³² Id.

¹³³ Id. at 235.

¹³⁴ Id. at 236 (proposing the example of hand washing, where a mandate would be difficult to enforce (as monitoring would be very costly) but nudges can be used to facilitate compliance). While such nudges may be effective even without a mandate, some forms of nudging do require a mandate in the background (e.g., when the nudges is to remind people of their obligation) and hence can be properly classified as a complement.). Id.

¹³⁵ See generally Valerio Capraro et al., Increasing Altruistic and Cooperative Behaviour with Simple Moral Nudges, 9 Sci. Rep. 1, 7 (2019).

¹³⁶ See, e.g., Nissim Cohen & Hadar Yoana Jabotinsky, Nudge Regulation and Innovation Policy, at 14 (Mar. 5, 2020) (unpublished manuscript), https://ssrn.com/abstract=3523910 [https://perma.cc/NKB5-B8MV].

¹³⁷ For instance, it has been argued that nudges during the COVID-19 pandemic worked well in Sweden because of the high degree of trust in the government, and that this is unlikely to carry over to areas with low trust. Jon Pierre, Nudges Against Pandemics: Sweden’s COVID-19 Containment Strategy in Perspective, 39 Pol’y & Soc’y 478, 480 (2020).

¹³⁸ See, e.g., Shane Frederick, George Loewenstein & Ted O’Donoghue, Time Discounting and Time Preference: A Critical Review, 40 J. Econ. Literature 351, 351 (2002).

¹³⁹ See, e.g., David Laibson, Golden Eggs and Hyperbolic Discounting, 112 Q.J. Econ. 443, 445-446 (1997); Gal Zauberman et al., Discounting Time and Time Discounting: Subjective Time Perception and Intertemporal Preferences, 46 J. Mktg. Rsch. 543, 544 (2009).

¹⁴⁰ For discussions of hyperbolic discounting in deterrence models, which most closely resemble what we consider in our example, see generally Thomas A. Loughran, Ray Paternoster & Douglas Weiss, Hyperbolic Time Discounting, Offender Time Preferences and Deterrence, 28 J. Quantitative Criminology 607, 613-14 (2012).

¹⁴¹ Zamir & Teichman, supra note 122, at 89.

¹⁴² See, e.g. Jiayu Li et al., Loneliness and Problematic Mobile Phone use Among Adolescents During the COVID-19 Pandemic: The Roles of Escape Motivation and Self-control, 118 Addictive Behav. 106857 (2021) (providing evidence on low self-control among teenagers during COVID-19).

¹⁴³ See Malte Friese et al., Is Ego Depletion Real? An Analysis of Arguments, 23 Pers. & Soc. Psychol. Rev. 107, 107-31 (2019); Nigel Harvey, Behavioral Fatigue: Real Phenomenon, Naïve Construct, or Policy Contrivance?, 11 Frontiers in Psychol. 1, 4 (2020) (discussing behavioral fatigue as a possible consequence of ego-depletion); Mogens Jin Pedersen & Nathan Favero, Social Distancing during the COVID‐19 Pandemic: Who Are the Present and Future Noncompliers?, 80 Pub. Admin. Rev. 805, 806 (2020) (“much research supports the concept of “behavioral fatigue” for pandemic prevention measures”); Ritwik Banerjee et al., Exponential-Growth Prediction Bias and Compliance with Safety Measures Related to COVID-19, Soc. Sci. & Med., Oct. 2020, at 8. (“Do we see evidence of such behavioral fatigue? While we do not have a direct measure of behavioral fatigue, we have a proxy relating to awareness: information bias…”); see, e.g., Richard Thaler, Some Empirical Evidence on Dynamic Inconsistency, 8 Econ. Lett. 201, 205 (1981). But see Derek Ireland, The Behavioral Ethics Challenges of Covid-19 Crisis to Recovery, 3 J. Mktg Mgmt. & Consumer Behav. 1, 32-33; 32 n.49 (2021) (discussing the scholarly controversy surrounding behavioral fatigue in the UK during the early days of the pandemic).

¹⁴⁴ See supra note 143.

¹⁴⁵ For a discussion of behavioral biases and heuristics in the context of the COVID-19 pandemic, see generally Teichman & Underhill, supra note 33.

¹⁴⁶ See generally Cass R. Sunstein, Behavioral Analysis of Law, 64 U. Chi. L. Rev. 1175, 1179-81 (1997).

¹⁴⁷ See generally Sarel, supra note 58, at §4.2.

¹⁴⁸ A higher willingness to take risks to avoid losses is consistent with the common theory in behavioral economics, known as “prospect theory.” See generally Daniel Kahneman & Amos Tversky, Prospect Theory: An Analysis of Decision Under Risk, 47 Econometrica 263 (1979); Amos Tversky, & Daniel Kahneman, Advances in Prospect Theory: Cumulative Representation of Uncertainty, 5 J. Risk & Uncertainty 297 (1992). For an overview of how the theory has been applied in economics, see Nicholas C. Barberis, Thirty Years of Prospect Theory in Economics: A Review and Assessment, 27 J. Econ. Persp. 173 (2013)). For an application of the theory in the context of COVID-19, see Sarel, supra note 58. For the impact of loss aversion in a crime-deterrence model, see Eberhard Feess & Roee Sarel, Optimal Fine Reductions for Self-Reporting: The Impact of Loss Aversion, Int’l Rev. L. & Econ. (forthcoming).

¹⁴⁹ Recent estimations (based on a meta-analysis) suggest that people that gains must be 1.8 to 2.1 times larger in order to be perceived as equal to a loss. Alexander L. Brown et al., Meta-analysis of Empirical Estimates of Loss-aversion 1 (CESifo Working Papers, Paper No. 8848, 2021).

¹⁵⁰ See Sarel, supra note 58.

¹⁵¹ See, e.g., Thaler, supra note 143.

¹⁵² Richard H. Thaler, From Cashews to Nudges: The Evolution of Behavioral Economics, 108 Am. Econ. Rev. 1265, 1267 (2018).

¹⁵³ Id.

¹⁵⁴ See van Rooij et al., supra note 17; Kuiper et al., supra note 14; Emmeke Barbara Kooistra et al., Mitigating Covid-19 in a Nationally Representative UK Sample: Personal Abilities and Obligation to Obey the Law Shape Compliance with Mitigation Measures 25 (Amsterdam L. Sch. Legal Studies Research. Paper No. 2020-19, 2020).

¹⁵⁵ George W. Burruss et al., Modeling Individual Defiance of COVID-19 Pandemic Mitigation Strategies: Insights from the Expanded Model of Deterrence and Protection Motivation Theory, 53 Crim. Just. & Behav. 1317, 1320 (2021).

¹⁵⁶ van Rooij et al, supra note 17, at 1 (“The present study assesses what factors influence Americans to comply with the stay at home and social distancing measures. It analyzes data from an online survey…”); Kuiper et al, supra note 14, at 1 (“We analyzed data from an online survey‥”); Kooistra et al, supra note 155, at 1 (“The present study assesses what factors influenced inhabitants of the United Kingdom to comply with lockdown and social distancing measures. It analyses data from an online survey‥”).

¹⁵⁷ See, e.g., Ananish Chaudhuri, Is the Price Right?: Fair Play and Economics, 19 U. Auckland Bus. Rev. 16, 24 (2016) (“One problem with survey evidence is that people’s survey responses and their real-life actions do not always match up.”). Partly for this reason, the field of “experimental criminal law” has emerged in recent years, emphasizing the validity of the results when people’s choices are actually measured. See generally Christoph Engel, Experimental Criminal Law: A Survey of Contributions from Law, Economics, and Criminology, in Empirical Legal Research in Action 57-108 (Willem H. van Boom et al. eds., 2018).

¹⁵⁸ See generally Vadim A. Karatayev et al., Local Lockdowns Outperform Global Lockdown on the Far Side of the COVID-19 Epidemic Curve, 117 Proc. Nat’l Acad. Sci. 24575 (2020).

¹⁵⁹ See generally Bhupendra Kumar Verma et al, Global Lockdown: An Effective Safeguard in Responding to the Threat of COVID‐19, 26 J. Evaluation Clinical Prac. 1592 (2020).

¹⁶⁰ See Cooter & Ulen, supra note 24, at 40-41, 102-03.

¹⁶¹ See Adam J. Kucharski et al., Effectiveness of Isolation, Testing, Contact Tracing, and Physical Distancing on Reducing Transmission of SARS-CoV-2 in Different Settings: A Mathematical Modelling Study, 20 Lancet Infectious Diseases 1151, 1154-56 (2020) (comparing combinations of policies in the UK).

¹⁶² Ryan Seamus McGee et al., Model-driven Mitigation Measures for Reopening Schools During the COVID-19 Pandemic, 118 Proc. Nat’l Acad. Sci. 1, 5 (Sept. 2021) (comparing proactive testing vs. vaccination of school teachers).

¹⁶³ See, e.g., Stefan Moritz et al., The Risk of Indoor Sports and Culture Events for the Transmission of COVID-19, 12 Nat. Commun. 1, 2 (Aug. 2021).

¹⁶⁴ See, e.g., Wei Lyu & George L. Wehby, Community Use of Face Masks and COVID-19: Evidence from a Natural Experiment of State Mandates in the US: Study Examines Impact on COVID-19 Growth Rates Associated with State Government Mandates Requiring Face Mask Use in Public, 39 Health Aff. 1419, 1420-21 (2020) (treating variance in adoption of mask mandates across the US as a natural experiment).

¹⁶⁵ For a brief overview of the literature on competition between regulators, see Giovanni Dell’Ariccia & Robert Marquez, Competition Among Regulators and Credit Market Integration, 79 J. Fin. Econ. 401, 404-06 (2006).

¹⁶⁶ Note that this bears resemblance to both the crime-displacement problem as well as the well-known concept of ‘regulatory arbitrage.’ See, e.g., Victor Fleischer, Regulatory Arbitrage, 89 Tex. L. Rev. 227, 247 (2010).

¹⁶⁷ See generally Shelly Kamin-Friedman & Maya Peled Raz, Lessons from Israel’s COVID-19 Green Pass Program, 10 Israel J. Health Pol’y Res. 1, 1 (2021); Luca Roncati & Monica Roncati, COVID-19 “Green Pass”: A Lesson on the Proportionality Principle from Galicia, 1 Eur. J. Health L. 525, 526 (2021); Ruth Waitzberg et al., The Israeli Experience with the “Green Pass” Policy Highlights Issues to Be Considered by Policymakers in Other Countries, 18 Int’l J. Envtl. Res. & Pub. Health 1, 2 (2021).

¹⁶⁸ For instance, Germany initially adoped a so-called “3G” rule, which grants equal liberties to the vaccinated (“Geimpft”), the recovered (“Genesen”), and the tested (“Getestet”). See, e.g., Zachary Desson et al., Finding the Way Forward: COVID-19 Vaccination Progress in Germany, Austria and Switzerland, Health Pol’y & Tech. 1, 9 (2021). Later on, a “2G” policy (i.e. only vaccinated and recovered) was also made available. See, e.g., Ned Stafford, Covid-19: Germany’s Doctors Call for Clear Rules to “Break Chains of Infection” as Cases Soar, BMJ (Nov. 12, 2021), https://www.bmj.com/content/375/bmj.n2783.full [https://perma.cc/EB8F-RR8Y].

¹⁶⁹ For a discussion of the rationales behind COVID-19 certificates and whether such certificates are proportional, see Roncati & Roncati, supra note 24, at 525-32; Evelyn Paris, Applying the Proportionality Principle to COVID-19 Certificates, 12 Eur. J. Risk. Reg. 287, 289 (2021); Iris Goldner Lang, EU COVID-19 Certificates: A Critical Analysis, 12 Eur. J. Risk. Reg 298, 300 (2021).

¹⁷⁰ This is analogous, for instance, to the issue of whether courts should follow precedents or invest effort into investigating the specific valuations that people assign to assets in a legal case. Efficiency requires that courts search for information only if the search costs are not too high. See Cooter & Ulen, supra note 24, at 88.

¹⁷¹ See generally Dionissi Aliprantis & Kristen Tauber, Measuring Deaths from COVID-19, 2020-18 Econ. Comment. 1 (2020); Thomas Beaney et al., Excess Mortality: The Gold Standard in Measuring the Impact of COVID-19 Worldwide?, 113 J. Royal Soc. Med. 329 (2020).

¹⁷² See generally Charles F. Manski, Vaccination Planning Under Uncertainty, with Application to Covid-19 (Nat’l Bureau of Econ. Research., Working Paper No. 28446, 2021).

¹⁷³ Id., John Mullahy et al., Embracing Uncertainty: The Value of Partial Identification in Public Health and Clinical Research, 61 Am. J. Preventive Med. e103 (2021).

¹⁷⁴ See generally Snigdha Gupta et al., Failed to Scale: Embracing the Challenge of Scaling in Early Childhood, in The Scale-Up Effect in Early Childhood and Public Policy 1 (John List et al. eds., 2021); Glenn W. Harrison, Field Experiments and Public Policy: Festina Lente, 5 Behav. Pub. Pol. 117 (2021). In the context of COVID-19 in particular, see also Rosanna W. Peeling et al., Scaling up COVID-19 Rapid Antigen Tests: Promises and Challenges, 21 Lancet Infectious Diseases e290 (2021).

¹⁷⁵ Gupta et al., supra note 174, at 5.

¹⁷⁶ Fragmentation and lack of universal data are also inhibitors of scaling. See id.

¹⁷⁷ See, e.g., Liesbet M. Peeters et al., COVID-19 in People with Multiple Sclerosis: A Global Data Sharing Initiative, 26 Multiple Sclerosis J. 1157 (2020); Sarah Engler et al., Democracy in Times of the Pandemic Explaining the Variation of COVID-19 Policies Across European Democracies, 44 West Eur. Pol. 1077 (2021); Global Initiative On Sharing All Influenza Data, https://www.gisaid.org [https://perma.cc/2ZBP-NDRU] (last visited Dec. 27, 2021). For an overview, see also Anna Bernasconi et al., A Review on Viral Data Sources and Search Systems for Perspective Mitigation of COVID-19, 22 Briefings Bioinformatics 664 (2021).

¹⁷⁸ John A. List et al., Combining Behavioral Economics and Field Experiments to Reimagine Early Childhood Education, 2 Behav. Pub. Pol’y 1, 14-15 (2018).

¹⁷⁹ Id. at 12-13.

¹⁸⁰ The evidence on scaling of nudges seems to be mixed. For instance, Stefano DellaVigna and Elizabeth Linos find that nudges adopted by two US “Nudge Units” yielded significant effects but smaller in size than those appearing in academic studies. See Stefano DellaVigna & Elizabeth Linos, RCTs to Scale: Comprehensive Evidence from Two Nudge Units (Nat’l Bureau of Econ. Research., Working Paper No. 27594, 2020). Converesly, Kelli A. Bird et al. find no effect of a large-scale nudge related to educational loans. Kelli A. Bird et al., Nudging at Scale: Experimental Evidence from FAFSA Completion Campaigns, 183 J. Econ. & Behav. Org. 105, 113 (2021). Furthermore, Justin E. Holz et al find that tax-related nudges worked on some types of firms but not others. See Justin E. Holz et al., The $100 Million Nudge: Increasing Tax Compliance of Businesses and the Self-employed Using a Natural Field Experiment (Nat’l Bureau of Econ. Research, Working Paper No. 27666, 2020).