674 HUMAN RIGHTS QUARTERLY Vol. 39 It has to be acknowledged that this approach was one of the first innovations in bringing quantitative methodologies to addressing the resources issue; it more reasonably links the performance expected of a duty-bearer to its level of resource availability (or, to be precise, to its level of financial resource availability). Indeed, the methodological approach set out in the remainder of this article has largely been inspired by it. It does, however, have numerous flaws. First, the SERF Index methodology provides very little normative account of the indicators that characterize social welfare attainment. Whether the indicators that underpin the SERF Index have been selected on the basis of a careful qualitative unraveling of human rights concepts or instead on the basis of operational ease is not evident. This lack of evidence by itself could suggest the latter. Second, and perhaps more importantly, the SERF Index is methodologically too simplistic to deal with the complexities that come with dealing with the resources dilemma for the purpose of measuring compliance. To reiterate the argument made earlier, maximum available resources are not limited to those of a financial kind. Consider also the heterogeneity of the countries included in the analysis. Outliers and statistical noise are likely.70 As a result, setting the boundary to the highest level of social welfare historically attained by any country leaves open the possibility—even probability—of it being hinged on very few extreme observations, with the vast majority of the data in fact lying far below it. This could potentially overestimate the degree of cross-country non-compliance to a significant extent. For example, the level of GDP per capita, PPP for Kenya in 2013 is roughly the same as that for the Philippines in 1994.71 If it is assumed, for illustrative purposes, that the Philippines attained the maximum level of health historically achieved at that given level of GDP per capita, does it make sense that Kenya be expected to achieve in 2013 the level achieved by the Philippines in 1994? Obviously the two countries differ in a number of significant ways. These differences may affect the residual, positively or negatively, regardless of the duty-bearer’s action or inaction. The level of social welfare that has previously been attained with the same given level of GDP per capita may then be too insensitive a target against which to measure compliance. Instead, the boundary must be set with a greater 70. The relationship between income and social outcomes is hardly linear. There are many countries with relatively low levels of income that achieve relatively high levels of social welfare: Cuba, for example. Likewise, there are many countries with relatively high levels of income that at the same time have relatively poor social outcomes: Kuwait, for example. 71. GDP per capita, PPP (current international dollars) was 2,843.351 for Kenya in 2013 and 2,764.781 for the Philippines in 1994. GDP per capita, PPP (current international dollars), World Bank , available at http://data.worldbank.org/indicator/NY.GDP.PCAP. PP.CD?locations=KE-PH.