In 2014, after three terms as New York's mayor, Michael Bloomberg resumed control of the eponymous company he founded in 1981. He has pledged to donate most of his $40.6-billion fortune.
What factors do you take into account when making a philanthropic investment?
The overall goal of Bloomberg Philanthropies is to make the biggest possible difference in the largest number of lives. To reach it, we look to invest in issues that aren't getting the attention they should. Road safety is a good example. Traffic crashes claim around 1.25 million lives every year, and that number will increase if we don't do anything, because the number of cars on the road is growing quickly. We also focus on cities, because what works in one city often holds valuable lessons for others. We try to bring together partners wherever and whenever possible. The private sector has resources and expertise that can benefit the public sector, and the public sector has the authority to scale up successful experiments.
How do you determine the return on investment in obesity prevention or green energy?
I've always believed, "If you can't measure it, you can't manage it." And if the data doesn't exist, we help gather it. To give you one example: Almost two-thirds of the world's deaths go unrecorded, and millions more lack a documented cause. So governments and other funders often don't have enough information to focus their resources, and they can't measure whether their efforts are working. Last year, along with the Australian government, we launched a project that will begin to address these problems by helping some of the countries with the most severe lack of health data gather more of it.