The Children's Society claims a good track record of meticulous research and Lily Caprani, its director of communications and policy, says: "If you are going to make big claims about why social issues such as poverty are important, you need to have the courage of your convictions that comes from having interrogated the evidence".
The charity's annual Good Childhood report is based on the first-hand knowledge gleaned from speaking to more than 40,000 children and teenagers since the project began in 2005. Such commitment to research bore fruit last September when, after an 18-month campaign by the charity that highlighted health, educational and employment benefits, the government announced that all school pupils under the age of seven would receive free school meals. "We'll always try to have some hard data to back up what we're saying," says Caprani. "I think that's one of the reasons we have been quite successful in influencing government."
There have been other recent campaign wins for charities that have used hard data to sway policy-makers. The Equality Act 2010 banned the use of pre-employment health questionnaires by employers after a campaign by Rethink Mental Illness and the National Aids Trust.
The crucial element was evidence from large firms such as BT that didn't use such questionnaires, showing that outcomes such as absentee rates were no worse. Victoria Bleazard, associate director of campaigns with Rethink Mental Illness, says: "It was only after we had gathered all that information from firms such as BT and got the CBI on board that we were able to get that change."
Bleazard is aware that data, frequently economic in nature, is invariably the decisive ingredient. "The emotive argument will rarely be the one that wins the day," she says. "We've had a number of meetings with Danny Alexander, the Chief Secretary to the Treasury, and his colleagues. They are good people at the Treasury - they want to do the right thing but, unless you've got an amazing economic analysis, they can't possibly give you anything because they have to ensure that the sums add up. If we could, we'd employ an economist."
There is an implicit assumption here that strong evidence will ultimately win out and convince policy-makers, but the support for evidence-based policy-making is patchy. On a range of subjects - from austerity to taxation, lobbying to welfare - government policy seems more grounded in ideological preference than hard data. Jay Kennedy, director of policy and research at the Directory of Social Change, says: "The last government pretended it wanted evidence-based policy, but I don't think this government really cares. It mostly wants to make decisions based on other factors. There could be compelling evidence in favour of a certain policy, but it's just no-go. They are not going to do it in a million years because it's the wrong type of beneficiary group."
Of course, amending government policy is not the be-all and end-all of campaigning. Drawing attention to a cause or influencing public attitudes are equally common and valid ambitions. "To be honest, sometimes we rely too much on data," says Caprani. "It's about balance - knowing you have the evidence but not relying solely on it. You don't reach hearts and minds with data alone."
Nonetheless, some believe the research underpinning the campaigns of the charity sector is not as solid as it should be. Duncan Craig is the founder and chief executive of Survivors Manchester, a charity that earlier this year successfully campaigned for ring-fenced government funding for male victims of rape (see case study). "I don't think the third sector is using statistics as we should do," he says. "We need to get better at using and sharing data."
He advocates an education campaign, spearheaded by councils for voluntary service, the local infrastructure umbrella body Navca and the National Council for Voluntary Organisations, to help organisations, especially small ones, use statistics to help their causes.
"At some point we are going to have to prove ourselves more than we have ever had to prove ourselves," he says. "I don't think it's all about data, but we have to start talking the same language as the people who hold the purse strings."
Case study: Break the Silence campaign
In February 2014, the Ministry of Justice announced a £500,000 fund specifically for male victims of rape and sexual violence. The announcement came after a sustained campaign, led by the charity Survivors Manchester but also involving Survivors UK and Mankind UK, that made use of statistics to demonstrate a need to fund dedicated services for men and boys.
The letter-writing campaign used statistics that showed a 48 per cent rise in the number of requests for support from Survivors Manchester in the wake of the Jimmy Savile inquiry. Police reports also showed that 10 per cent of rapes in major English cities were of men. Duncan Craig, chief executive of Survivors Manchester, used academic studies to demonstrate that 368,000 men in Greater Manchester might be in need of support. Further studies, estimating the cost of rape per person at £73,000, were invoked to highlight the expense of doing nothing. "We looked at government stats to show that 10 per cent of all reported rapes come from men and then asked what we were doing to help that 10 per cent," says Craig.