The inertia of self-regulation: a game-theoretic approach to reducing passive smoking in restaurants Alan Shiell a, *, Simon Chapman b a Social and Public Health Economics Research Group (SPHERe), Department of Public Health and Community Medicine, University of Sydney, NSW 2006, Australia b Department of Public Health and Community Medicine, University of Sydney, NSW 2006, Australia Abstract Two alternate regulatory approaches can be used to reduce exposure to environmental tobacco smoke in workplaces. The ®rst is voluntary, self-regulation introduced by management, which is supported by common law and occupational health legislation that emphasises the employers' `duty of care'. The second is public health legislation that bans smoking outright in enclosed places. In Australia, self-regulation has succeeded in restricting tobacco smoking in most indoor workplaces but has been a relative failure in the hospitality industry. Claims that this re¯ects consumer preference by diners, club and hotel patrons are not backed by survey evidence, typically showing large majority support for non-smoking establishments. Insights from game theory show why reliance on the duty of care is unlikely to succeed even when establishment operators collectively support a non-smoking policy. Using plausible assumptions about the net costs of unilaterally introducing smoking restrictions, what makes good sense for society as a whole is likely to be the least pro®table option for an individual operator acting alone. Operators ®nd themselves in the classic prisoner's dilemma. If the aim of policy is to restrict smoking in public places in order to protect the health of employees then game-theory predicts that public health legislation banning smoking in enclosed places will be more eective than self-regulation and reliance on the duty of care. 7 2000 Elsevier Science Ltd. All rights reserved. Keywords: Passive smoking; Game theory; Tobacco control; Prisoner's dilemma; Regulation Introduction A recurrent theme in debates about the ethics of public health interventions is the con¯ict that arises between respect for individual autonomy and the desire to promote population health. This con¯ict has been often exempli®ed in the case of tobacco smoking (Sul- lum, 1998). Tobacco use has been identi®ed as the single largest threat to population health (US Depart- ment of Health and Human Services, 1989). The adverse eects of tobacco use and its high social and economic costs have been used to justify restrictions on the availability and advertising of tobacco products and the spending of public money on smoking cessa- tion campaigns (Armstrong, Daub & Shean, 1988). However, some argue that the costs of tobacco use and its health consequences are borne knowingly by smokers whose consumption decisions are made after balancing the risks and costs of tobacco against the Social Science & Medicine 51 (2000) 1111±1119 0277-9536/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved. PII: S0277-9536(00)00018-6 www.elsevier.com/locate/socscimed * Corresponding author. Tel: +61-2-9351-5127; fax: 61-2- 9351-7420. E-mail address: alans@pub.health.usyd.edu.au (A. Shiell).