Chapter 1 | Page 8 domestically and through international co-operation. It also proposed some ‘indicators’ that can be applied to measure State compliance in the context of resources. These include expenditure on ESC rights as against other expenditures within the State, comparisons with other States and comparisons against internationally identified indicators of human rights and human welfare.21 The ESCR Committee has also made further reference to ‘maximum available resources’ in a number of General Comments and Concluding Observations on the periodic reports of States parties under the ICESCR. However, despite these multiple references to States’ use of ‘maximum available resources’ for the realisation of ESC rights, the nature of this obligation and what it implies in ESC rights policy and practice remain unclear at the practical level. A preliminary review of ESC rights scholarship indicates a recognition of the difficulties involved in unpacking ‘maximum available resources’ in a manner applicable to ESC rights policy and practice and the need for a broader interpretation.22 It is acknowledged that the formulation of this phrase is ‘vague and imprecise’23 and requires a more ‘dynamic’ understanding.24 The phraseology of ‘maximum available resources’ creates difficulties not only in the interpretation of other related concepts in the article, but also makes monitoring of progressive realisation and State compliance more challenging. Key interpretive challenges identified in the literature include: comprehensively defining ‘resources’; determining what resources are actually ‘available’ to the State; and identifying a ‘maximum’ of resources in relation to ESC rights policy 21 Ibid. 22 For example, Balakrishnan et al, above n 14, 23; Manisuli Ssenyonjo, 'Reflections on state obligations with respect to economic, social and cultural rights in international human rights law' (2011) 15(6) The International Journal of Human Rights 969-1012; Robert E Robertson, 'Nutrition , human rights and resources' (1996) 21 Food Policy 57-71; Robertson, above n 16; Felner, above n 17; Audrey Chapman, 'The Status of Efforts to Monitor Economic, Social, and Cultural Rights' in Shareen Hertel and Lanse Minkler (eds), Economic Rights: Conceptual, Measurement, and Policy Issues (Cambridge University Press, Cambridge, 2007) 143. 23 Chapman, above n 22, 148. 24 For example, see John Tobin, The Right to Health in International Law (Oxford University Press, Oxford, 2011), 229.