Law and urban governance for health in times of rapid change.

Governance is an important factor in urban health, and law is an important element of healthy governance. Law can be an intervention local government wields to influence behavior and shape environments. Law can also be an important target of health promotion efforts: Law and the enforcement and implementation behaviors it fosters can promote unhealthy behaviors and environmental conditions, and can act as a barrier to healthy interventions or practices. Finally, law is a design and construction tool for the organization of governance. Law is the means through which cities are formally established. Their powers and duties, organizational structure, boundaries and decision-making procedures are all set by law. Regardless of the form of government, cities have legal levers they can manipulate for health promotion. Cities can use tax authority to influence the price of unhealthy products, or to encourage consumption of healthy foods. Cities can use their legal powers to address incidental legal effects of policies that they themselves cannot control. Cities may also have the authority to use law to address deeper determinants of health. The overall level of income or wealth inequality in a country reflects factors well-beyond a local government's control, but city government nonetheless has levers to directly and indirectly reduce economic and social inequality and their effects. A renewed focus on law and urban governance is the key to assuring health and well-being and closing the health equity gap.