"The EU is basically the only bloc of countries that promised to reach the GNI target of 0.7 percent… I think what is different about the EU is that they set a deadline," Tamira Gunzburg, the Brussels director of ONE, an international anti-poverty organization, told CNBC.
ODA remains contentious, with critics saying that it can serve to further donors' rather than recipients' needs or create dependence. Others say that richer countries may lack insight into the needs of recipients or that aid can be misused by beneficiaries. However, aid can provide a lifeline for countries facing humanitarian crises or too impoverished or unstable to attract private funding.
As part of the explanation as to why Europe gives proportionately more ODA, Gunzburg noted that countries with bigger welfare states — like those for which the Scandinavian nations are famed — tend to pay higher taxes, leading to more government revenue that can be spent on aid.
For instance, in Sweden — which had the highest ODA/GNI ratio in 2014 of 1.1 percent — those on the biggest wages pay national income tax of 25 percent and municipal income tax of around 32 percent. These rates are levied on anybody earning 616,100 Swedish krona ($74,991) or more.
By comparison, in the U.S., the highest federal tax rate of 39.6 percent is only levied on single filers earning $413,201 or more. An additional state tax is also imposed, which for the highest payers varies between roughly 3 percent and 12 percent, with federal income tax deductible in some states.