Mr. Lomborg is the founder of an international think tank called the Copenhagen Consensus Center. He has invented a useful method for dispassionately but expertly deciding how to spend limited funds on different priorities. Every four years since 2004, he has assembled a group of leading economists to assess the best way to spend money on global development. On the most recent occasion, in 2012, the group—which included four Nobel laureates—debated 40 proposals for how best to spend aid money.
The goal was simple: to create a cost-benefit analysis for each policy and to rank them by their likely effectiveness. For every dollar spent, how much good would be done in the world?
The numbers produced by this exercise are eye-catching. Every dollar spent to alleviate malnutrition can do $59 of good; on malaria, $35; on HIV, $11. As for fashionable goals such as programs intended to limit global warming to less than two degrees Celsius in the foreseeable future: just 2 cents of benefit for each dollar spent.
Nor is this just about the cold tabulation of dollars and cents. The calculus used by the Copenhagen Consensus also includes such benefits as avoided deaths and sickness and potential environmental benefits, including forestalling climate change.