THE unintended consequences of government policy constitute a major theme for economists studying the welfare impact of policy and regulations. Adam Smith's famous "invisible hand" is an example of the unintended favourable effects of laissez faire. Most often, however, "the law of unintended consequences" has served to illustrate the adverse unanticipated effects of legislation and administrative regulations.

This applies as well to one of the most confounding policy challenges of the age: mitigating and adapting to climate change. Examples of the law at work can be seen at the global as well as the local and regional levels. The recent announcement of the Singapore government's plans for "outreach efforts" on climate change awareness makes these examples all the more instructive.

At the global level, there is the recently concluded UN climate change conference (COP 23) in Bonn. Even before the conference had ended, there were pointed headlines in the media that referred to Germany, the darling of the environmental movement, as the "hypocrite" in the crowd of nations gathered in Bonn. Its leading national news magazine, Der Spiegel, titled its front page article "Germany under fire for climate change hypocrisy".