Do you do Twitter? It is a playful but also a powerful medium. You can amuse, annoy, proclaim, inform, report, and certainly upset. Sometimes a few informal words can lead to a much more thoughtful response. On one dark winter's night recently, I sent a stream of tweets about the impact of economic thinking on health. I have witnessed the power of economics to strengthen the case for investments in global health. I have seen economists take an increasingly important and valuable leadership role in shaping the debate about development assistance for health. And in thinking about sustainability for the post-2015 era, I have been grateful to economists for emphasising that traditional ways of thinking about economic growth simply do not apply when sustainability is our chief concern. But there is a but. The tenets of economics—the centrality of the market, the importance of competition—have begun to influence, distort, and damage the values on which universal health systems were originally built. Economic instrumentalism, the notion that unless we can prove the economic value of an idea or an intervention it is socially worthless, is now dominant in much of government. We see institutions supposedly dedicated to health now incorporate wealth into their mission statements. The health community has too often colluded with politicians to appease economists who measure value with a financial metric only. It's surely time to challenge economists, their discipline and their arguments, and counter with an alternative philosophy that puts lives ahead of margins and wellbeing before returns on investment. The following essay is a rebuttal by three respected economists who strongly disagree with the ten tweets I sent. I hope this dialogue provokes you to tweet too. Economics should incorporate ethical considerationsIn support of Richard Horton's idea that “economists have stripped morality from economics”,1 I identify two issues with health economics: first, the conservatism of positive economics (the descriptive branch), and second, the way values are illicitly transported from positive economics to normative economics (the prescriptive branch). Full-Text PDF