Coiera and Braithwaite suggest market-based controls for improving patient safety in their thought-provoking exploratory essay,1 but potentially adverse effects on equity of care for vulnerable populations must be addressed (see page 99). The authors identify the key components of market-based controls as decentralisation and “individual agents making local decisions about allocation.” The invisible hand of Adam Smith represents the view that the free market maximises overall effectiveness and efficiency.2 The market will have winners and losers, but overall utility is maximised. However, the classic critique of market-based approaches is that they ignore externalities, that is, costs or benefits that affect third parties who cannot directly impact the business transaction. For example, equity of care for vulnerable populations may suffer. While Coiera and Braithwaite argue that market-based controls are a specific mechanism rather than an ideological philosophy, free-market principles are cornerstones of the plans.

We highlight and discuss the critical equity issues in the market-based control schemes proposed by Coiera and Braithwaite. While we are unaware of any prior studies on market-based controls in patient safety, an extensive literature from the global warming, emissions trading and carbon tax fields informs us about concerns to address and pitfalls to avoid. We summarise the main equity concerns of economic and regulatory experts,3 and scholars from the “development critique” school of thought that criticises modern colonialism.4 We discuss the applicability to patient safety of these critiques of emissions trading approaches. We then conclude with several principles on how equity should be addressed in market-based control schemes to improve patient safety.

New strategies to reduce global greenhouse gas emissions have adopted the structure of market-based control in place of command-and-control regulations or taxation of emissions.34 For example, a framework proposed in the Kyoto …