increase in the spending on health, education or social housing. But resources are finite, and tradeoffs may be required. Other benchmarks have been proposed, however, also with a view to assessing States' efforts, but focusing on specific rights, based on an estimate to what is required to fulfil them at the appropriate level. The World Health Organization for instance, estimated in 2012 that the "minimum spending per person per year needed to provide basic, life-saving services" represented 12 USD. During that same year, the average amount spent on healthcare in OECD countries was 4,380 USD per person and per year; in the United States, with a record 8,362 USD per person and per year, the spending was almost double that average for rich countries. However, the respective contributions of households and of the State diverged widely from country to country: whereas Luxembourg had the highest level of public spending on health per person and per year (with 6,906 USD, which compares to the meagre 2 USD/person/year Myanmar spent in 2010), Switzerland has the highest level of private spending (or out-of-pocket spending per household), with 2,412 USD.195 As we have seen, other (more recent) studies have proposed more ambitious targets, both absolute (86 USD per person per year in the 2014 Chatham House report, for instance) and as a percentage of the country's GDP (5 percent, according to that same report).196 This is a higher estimate even than the one proposed in the 2010 World Health Report, which concluded that low-income countries would need to spend on average 60 USD per capita by 2015 in order to deliver a set of essential health interventions.197 We are concerned here, not with the numbers as such, but with the methodological questions raised by such an attempt. There is broad agreement on some issues. It is clear, for instance, that it is more appropriate to define a target in terms of governmental expenses (public spending) as a percentage of the GDP, rather than in terms of the percentage of total governmental spending that should go to a sector such as healthcare. A target expressed as a percentage of public spending198 obviously ignores the fact that some States may have a much larger public sector than others, and that States in which the public sector is least developed may have far more unused fiscal space. It is also clear that the same levels of investment may have more or less impact on the fulfilment of the right to health, depending on how efficiently the resources are used and, in particular, on whether they go to meeting the priority needs of the population, particularly those of the low-income groups within the population. Thus, who is reached matters, at least as much as how much governmental spending goes to any particular sector. And far more attention should go to combating inefficiencies: the Institute of Medicine in Washington D.C. for instance estimated that in 2009, more than a third of health care costs in the United States were unnecessary or wasted, for a total amount ranging between 750 and 765 billion USD.199 These problems are similar to those already noted regarding the UNDP proposal to define a human expenditure ratio as a target for States to reach on "human priority" programmes. Other illustrations could be provided for other social rights. For instance, Unicef has presented a model to assess the financial needs of the education sector, taking into account a number of variables such as the number of children to be educated (itself a function of the percentage of school-age children in the total population), the desirable pupil-teacher ratio (40 being the target), the recurrent funding to cover salaries and materials, and the additional costs of enrolling marginalized children; and capital 195 All these figures, based on 2010 data, are from the WHO factsheet No. 319: Spending on Health: A global overview (April 2012), available on: http://www.who.int/mediacentre/factsheets/fs319/en/# (last consulted on 18 October 2016). 196 See above, text corresponding to note 86. 197 World Health Organization (High-level Taskforce on Innovative International Financing for Health Systems), More money for health and more health for the money (WHO, 2009). 198 See, for instance, the Abuja Declaration on HIV/AIDS, Tuberculosis and Other Related Infectious Diseases, adopted at the African Summit on HIV/AIDS, Tuberculosis and Other Related Infectious Diseases, convened in Abuja, 26-27 April 2001 (in which the Heads of State and Government of the Organisation of African Unity (OAU) pledged to allocate "at least 15% of our annual budget to the improvement of the health sector") ((OAU/SPS/ABUJA/3) (available at: http://www.un.org/ga/aids/pdf/abuja_declaration.pdf), at para. 26). 199 Institute of Medicine, Best Care at Lower Cost: The Path to Continuously Learning Health Care in America (Institute of Medicine, Washington, DC: National Academies Press, 2013). 42