The Grand Convergence is the Big Idea of the Lancet Commission on Investing in Health. It is the idea that by 2035 the poor world could have similar mortality to the rich world. Is it achievable? Can it bring the “fractious global health community” together into one aim to replace the Millennium Development Goals? The report of the commission was published earlier this week and launched at a meeting in London.

For most of human history child mortality was high, life expectancy was low, and health status was poor, said Larry Summers, cochairman of the commission and once Secretary of the Treasury in the Clinton Administration, chief economist at the World Bank, and president of Harvard University. About two centuries ago science, economic growth, and public health began to mean that health status improved in the rich world.  By 1993 child mortality differed by a factor of 30 between the rich and poor worlds. This was the Great Divergence. The year 1993 is important because that was the year of the World Development Report, which created huge controversy but also shaped the development world. The Lancet’s commission, which is cochaired by two authors of the original report, hopes to achieve the same, and judging by the reaction of some of the Big Dogs at the London meeting it may succeed.

We know that it is possible for poor countries to reduce mortality to the level of that in rich countries because the “4 Cs” (China, Cuba, Costa Rica, and Chile) have done it. The gains come from reduced mother and child deaths and deaths from infectious disease, particularly AIDS, TB, and malaria. But will the necessary investment be forthcoming?

It makes economic sense to invest in health, said Summers, because it leads to a more productive workforce, people are willing to save more, and the next generation is better educated and more productive. Economists can put a number on this, and these reasons alone lead to a “return on investment.” (Just in case there are some readers who don’t understand this term it means that if you invest a dollar you get more than a dollar’s worth of benefits back—it might be more dollars or benefits that have a high dollar value). But, said Summers, individuals want to live longer, and economists have put a value on how much people are willing to spend to live a year longer. When this value is added to the sums it increases dramatically the return on investment—to a very high nine to 20. Few investments produce such a high return, and it means, said Summers, that investing in health is not high risk: even if you can’t achieve a return of 20 you can be confident of achieving some return.

These statements worried me, and I asked Summers if the commission was assuming that all investments in health were beneficial (when I know they are not) and whether the value of a life gained included a life with dementia and multiple problems? The calculation does assume wise investment, mostly in low and middle income countries, where an extra year of life can be gained at much lower cost than in high income countries, and the measurement of how much people will pay does include people recognising that the quality of the extra year may be low. (But do people know how low? Do any of us? “Is my demented mother happy?” is a question I ask myself regularly and find unanswerable.)

The Grand Convergence, continued Summers, will save 10 million lives in 2035 and annually thereafter, and the cost will be $70 billion, which is less than 1% of the extra GDP resulting from expected growth. Most poor people are now in middle rather than low income countries, and these countries can fund the investment themselves. International aid will be needed for the poorest countries.

Summers declared himself “deeply impressed by the opportunity before the world over the next generation.” Success, he added, will breed new challenges. As maternal and child deaths and deaths from infectious disease fall, deaths from NCD (now the preferred term for non-communicable or chronic disease) will rise. This has already happened in Bangladesh, where I was last week: NCD accounted for just 10% of deaths in 1986, now it’s 80%. But there are interventions that can make a big difference, particularly big increases in tobacco tax and a reduction in subsidies for fossil fuels. A 50% increase in tobacco tax over 50 years will both save 20 million lives and bring in revenue of $20 billion a year, a “best buy” if ever there was one. Many low income countries currently spend more on fuel subsidies than they do on health, which is understandable as a response to the power failing regularly in hot countries. But reducing fuel subsidies will improve the quality of the air and reduce deaths in low income countries. (When I flew out of Dhaka on Monday the city quickly disappeared in the smog.)

The commission supports pro-poor universal healthcare and is not, said Summers, enthusiastic about user fees. It’s pragmatic about some private sector provision of care but favours universal financing—either through taxation or compulsory insurance.

Funding on research and development should be doubled from $3 billion a year to $6 billion. The emphasis should be on implementation research, providing information on which interventions are most cost effective. People in the audience doubted that this would be enough, but Dean Jamieson, co-chair of the commission and professor at the University of Washington, explained that implementation research is cheap compared with the investment to produce, say, an AIDS vaccine. Funds will also be needed for infection security, and Summers said how horrified he had been to discover that the WHO infection security budget is less than that of New York City.

The strongest criticisms of the report came from Anthony Costello, a professor at University College London, who said that this was the usual Lancet report suggesting that technology plus investment will be enough. It failed to recognise that “technology never works without social change.” Child mortality has been progressively declining and grand enterprises like Alma Ata and the Millennium Development Goals have not led to step changes in the decline. Costello was doubtful that with the state of the global economy funds would be adequate and pointed out that the word “sustainability” appeared only once in the 68 page report.

I too worried that insufficient attention is paid to climate disruption. A day before the meeting I read these words in the Economist. “Everyone knows what must be done about climate change, but no one is doing anything about it. More than two decades of speeches and summitry have failed to thin out emissions of greenhouse gases. In fact, emissions are accelerating: a quarter of all the carbon dioxide ever pumped into the air by humans was put there in the decade between 2000 and 2010. It will hang around for centuries, meaning that the future is sure to be hotter, even if all greenhouse gas emissions cease overnight. The official ambition of limiting the global temperature rise to 2°C looks increasingly like a bad joke.”

Something’s gone awry when the Economist is taking a tougher line on climate change than the Lancet. Somebody in the audience also made the point that population pressure and shortages of food and water could mean that we go backwards rather than forwards with health. Costello supported this, saying that food production could be hit very early by climate disruption.

But most of those at the meeting, including Big Dogs from the World Bank, the Global Fund, WHO, the IMF, USAID, the Gates Foundation, and DFID, supported the report. Richard Feachem, professor  at University of California, San Francisco, pointed out that the Grand Convergence could be achieved for an annual expenditure of $24 per person when the US is spending $8000 and Europe $5000. A former head of the Global Fund, he thought that the fund would soon broaden its agenda and might become the Global Fund for the Grand Convergence. He thought too that it could stop those in global health arguing for their particular interest and become the health goal within the Sustainable Development Goals, the goals that will follow the MDGs.

Competing interest: RS spoke at the meeting in the panel on NCD.

Richard Smith was the editor of the BMJ until 2004 and is director of the United Health Group’s chronic disease initiative.