'EA makes people feel confident about giving' The criticism of fundraising practices and chief executive salaries in the media over the past year is likely to be a factor that led to the finding in a recent survey that trust in charities is at its lowest point since 2007. Could this represent an opportunity for effective altruism? Sam Deere, director of communications at Giving What We Can, part of the Centre for Effective Altruism, says charity sceptics are not a majority of the adherents of effective altruism, but people who are disillusioned about charities do seem more open to it than other forms of giving. "It's a much better proposition for someone who is sceptical about charities," he says. "There's a broad range of things that EA has a good answer to because we've done rigorous research. That's definitely comforting and makes people feel more confident about giving to charity." Paul Vandenbosch, a GP from Surrey who considers himself an effective altruist (see case study, below), says that concern about how his money would be used by charities was one of the motivations for starting to donate to organisations endorsed by effective altruism. He says he finds it reassuring that the charities recommended by charity evaluators associated with the movement are all highly transparent. But Robert Penna, a charities consultant who co-wrote a critical blog on effective altruism for the Stanford Social Innovation Review in 2013, says he does not believe recent negative media coverage of mainstream charities represents any kind of threat to current giving patterns. "I really don't think stories like this represent an opening for effective altruism," he says. "I don't think charities - particularly the big boys - have got anything to worry about because, within the sector, it's a relatively fringe idea favoured by insiders. People are going to continue going to the brand names they know - the ones that do the big, slick fundraising campaigns."

If you could choose between providing a guide dog to help one blind person and completely curing the blindness of more than 700 people in a developing country, what would you do? Each would cost about £50,000, and the leaders of a growing social movement known as effective altruism argue that people who want the greatest impact from their charitable donations should think twice about supporting Guide Dogs rather than a charity than can restore the sight of hundreds for the cost of one dog.

Maximising the good you do by donating to the most effective charities in the most deserving cause areas is at the heart of EA, as the supporters of effective altruism call it. Many people give to charity because they have a personal connection, as when they give to a cancer charity because a relative died of cancer. But EA supporters say they should instead make their giving decisions on the basis of evidence about where the money will make the greatest difference. They also encourage people to donate 10 per cent of their annual incomes.

The EA movement has been growing since 2007, when the US-based charity evaluation service GiveWell was founded. GiveWell carries out research on charities it considers promising to come up with four or five organisations it claims to be the most effective in the world, and it urges people to adjust their charitable giving accordingly. Its influence appears to be rising: donations generated by its endorsements have, it says, risen from $3m in the years 2007 to 2010 to $100m in 2015.

Two top charities

Two UK-based charities, Against Malaria Foundation and the Schistosomiasis Control Initiative - which focuses on an infection, also known as bilharzia, caused in the developing world by a parasitic worm - are among GiveWell's top charities for 2016. They have also been recommended for their effectiveness by Giving What We Can, another charity evaluator, which is part of the UK-based Centre for Effective Altruism.

Sam Deere, director of communications at GWWC, says the double endorsement of these charities has not only significantly boosted their voluntary income, but also improved their credibility with funders that have the capacity to donate millions. He says SCI was able to point to the GWWC analysis of its effectiveness when it applied to the Department for International Development and received a grant of £10.5m to treat schistosomiasis in eight countries.

These examples clearly show the benefits to the charities endorsed by effective altruism. But have charities that are rated less effective - or not rated at all - lost funding as a result?

"I wouldn't think so, because we're encouraging people to donate more, so more dollars should be going into the charity sector as a result of what we're doing," says Deere, whose organisation asks members to pledge to give away 10 per cent of their incomes throughout their lives. "We don't see this as leaching money away from less effective charities - rather, that we're increasing the available funds."

But some effective altruists have criticised individual charities. William McAskill, an associate professor of philosophy at Oxford University and co-founder of GWWC, says in his 2015 book Doing Good Better that "mega-charities" such as World Vision, Oxfam or Unicef would not be endorsed by the effective altruism movement because they run multiple programmes and are therefore very difficult to evaluate. "If a charity implements a variety of programmes, inevitably some of these will be more effective than others," he says in the book. "In which case, we should simply focus on funding those very best programmes."

McAskill has praised Oxfam for publishing impact reports about its programmes, including those that were ineffective, while adding that the charity could do more to improve its impact. At a London event about effective altruism last November, he said: "I'd like Oxfam to go even further - not just to evaluate things after the fact, but to make strategic decisions. To say 'we know this is an area worth focusing on and we can see the evidence behind it,' rather than focusing on causes for other reasons."

It is not known whether any Oxfam donors have rejected it in favour of EA-endorsed charities, but McAskill's comments have gained the attention of Mark Goldring, chief executive of Oxfam GB, who attended the November event. Goldring says that effective altruism is commendable in that it is likely to improve charities and increase charitable giving, but thinks its focus on how much impact donations achieve is too rigid.

Case study: Charities that target mosquitoes and worms The Against Malaria Foundation, a Hertfordshire-based charity that distributes insecticide-treated bed nets to poor households in Africa, is the most highly recommended charity by GiveWell, the main charity evaluation service associated with the effective altruism movement. AMF was first named as GiveWell's top charity in 2011, and has been rated as one of the world's most effective charities every year since then except 2013, when GiveWell believed it did not have the capacity to spend additional funding as effectively as before. Rob Mather, founder and chief executive of AMF, says the endorsement has led to more than £35m being donated to the charity over the past five years, over half of which has come from the effective altruism community, mostly in the US. This included a £16m donation in December from San Francisco-based Good Ventures, a US-based foundation that is working closely with GiveWell to determine how to spend its money effectively. GiveWell's endorsement of AMF has proved extremely valuable, and when it was withdrawn for a year in 2013 the charity's income quickly fell from £5m to £3m. But Mather says AMF will never exploit the endorsement by running advertising campaigns highlighting its supposed status as the world's most effective charity. "I wouldn't do a big marketing campaign because I believe our time is best spent on programme work," he says. The organisation rated second best on GiveWell is the Schistosomiasis Control Initiative, which supports programmes in Africa that treat people for parasitic worm infections, or bilharzia. SCI, a non-profit initiative that is housed at Imperial College London, has been a top GiveWell charity since late 2011. Alan Fenwick, director of SCI, says the charity used to receive all its funding from governments and foundations and had no voluntary income before being recognised by GiveWell. "The impact GiveWell and Giving What We Can has had on us is huge," he says. "They raise about £5m for us each year, of which £3m comes from three high-net-worth individuals."

Goldring says it would be wrong to apply the EA philosophy to all of Oxfam's programmes because it could mean excluding people who most need the charity's help. For a certain cost, the charity might enable only a few children to go to school in a country such as South Sudan, where the barriers to school attendance are high, he says; but that does not mean it should work only in countries where the cost of schooling is cheaper, such as Bangladesh, because that would abandon the South Sudanese children.

Another of Goldring's objections to the EA philosophy is shared by Jonathan Glennie, director of policy and research at Save the Children, which GiveWell has not recommended - or even evaluated - partly because it does not believe the charity focuses enough on what EA considers to be priority areas, such as administering vaccinations or treating tuberculosis.

Glennie, who spoke at a Giving What We Can event for Cambridge University students in January, says he believes that by favouring charities working on evidence-based interventions, effective altruists risk neglecting the need for systemic change that addresses the root causes of poverty: an example he gives is the distribution of insecticide-treated nets in malaria-prone areas, which is the Against Malaria Foundation's main activity. He says the movement ought to have a more comprehensive view of what constitutes effectiveness, which should include campaigning.

"There's a lot we can't apply science to, such as political negotiation and struggle, which is sometimes the most important and effective thing of all," he says.

Provoking debate

Goldring and Glennie are sceptical about certain aspects of effective altruism, but the fact that senior representatives of two of the largest charities in the UK are engaging with it does indicate that it provokes debate in the sector. EA remains far from being a mainstream way of giving to charity, however. Robert Penna, the US-based author of The Non-profit Outcomes Toolbox, a guide to charity effectiveness, says: "Outside the sector it is virtually unknown." Why is this?

Penna believes most people are motivated to give by emotion, do not consider their giving in a strategic way and struggle to relate to a highly purposeful idea like effective altruism. "I don't think the movement would work for most people because it presupposes a level of engagement and knowledge the public does not have," he says. "Most people consider their giving not in the aggregate but as individual dollops."

Deere of GWWC says the movement has been in existence for less than a decade and is just getting started. But he also believes that many people - particularly in the charity sector - might be resistant to effective altruism because they don't want to accept they might not have been directing their energy or donations into the most effective areas.

"It's difficult for people to think that this thing they've given so much of themselves and their time to might not actually have been the best use of that time," he says.

Deere hopes that in the coming years the movement will grow to the point at which it is the dominant rationale for giving to good causes.

"Most people give to charity because they really want to make the world a better place," he says. "To do that, you need to start making some of these choices. Most people who think about these ideas for any length of time are at least broadly convinced."

Case study: The GP living the altruistic life

When Paul Vandenbosch (right) first discovered effective altruism four years ago, he had already been living a more altruistic life than most. In 2009, the 61-year-old GP from Surrey donated a kidney to a stranger. He had earlier spent two years volunteering in Zambia for the development charity VSO.

Then, in 2012, he read The Life You Can Save, a book about ending world poverty by the Australian philosopher Peter Singer, one of the founders of the effective altruism movement. Vandenbosch was so inspired that he decided to follow Singer's recommendation to pledge a percentage of his income to highly effective aid organisations.

"It was very interesting that somebody should write so much about how you can be effective and identify charities that met those criteria," he says. "I've always been aware of my own relative prosperity and feel that anyone who is wealthy should be giving a significant proportion of their income."

Vandenbosch had already been giving 10 per cent of his income to charity before he signed the pledge, but says it is useful to have a target to remind him - not least because his income will fall when he retires. As well as donating to the GiveWell-recommended charities the Against Malaria Foundation and the Schistosomiasis Control Initiative, he continues to donate to non-endorsed charities with which he has a connection, such as VSO.