This paper proposes that despite the vast amounts of money spent by philanthropists, they fall far short of solving the most pressing problems. Kramer argues that closing the gap between investment and results requires a new approach: ‘catalytic philanthropy’. Rather than assuming that more money will increase the likelihood of success, catalytic philanthropists follow four precepts: (1) they take responsibility for achieving results, by proactively thinking about how to solve a specific problem rather than reacting to requests from non-profit organisations (2) they mobilise campaigns for change by stimulating cross sector collaborations and mobilising stakeholders to create shared solutions, (3) they use all available tools, complementing traditional grant-making with resources such as investment capital, corporate resources, advocacy,litigation and lobbying, and (4) they create actionable knowledge by using information they gather about the problems they are tackling to illuminate their own actions and motivate the actions of others. Kramer concludes that many donors have neither the time nor resources to do more than contribute to deserving organisations, and can still do a good job of assisting individuals and enriching lives. But donors who are serious about changing the status quo must become catalytic philanthropists in order to make meaningful social progress.