20 72. However, the Commission believes that the argument concerning the progressive realization of the DESC does not apply to the instant case, because the quality, nature or scope of the survivor’s pension or the service provided by health services in Colombia is not at issue. Instead, what is at issue is the application of a domestic norm that establishes exclusion for same-sex couples with regard to pension rights. The State, moreover, has neither argued nor demonstrated that Mr. Duque was unable to access the survivor’s pension because of the country’s economic or technical limitations. Furthermore, according to the facts established in this case, because of the mandatory nature of social security and the contributions that Mr. JOJG made, the material conditions were there for Mr. Duque to get the medical treatment he required, simply by ensuring his continued enrollment in the contributorbased health services regime. 73. The Commission notes that, in the instant case, the State submits that the concept of “progressive realization”, when applied to social security rights, would allow to gradually extend the coverage group by group; hence, it argues, the denial of pensions to same-sex couples is a problem that has been remedied with the passage of time. However, the IACHR has already established that “the first obligation ‘with immediate effect’ arising from economic, social, and cultural rights consists of ensuring that those rights shall be exercised in conditions of equality and without discrimination”.55 That is to say that, while implementation of the ESCR involves an obligation of “progressive realization”, the latter cannot be discriminatory.56 In the instant case, the State has not explained what objective reason —and necessary according to the standard of strict scrutiny— would justify access to pension rights in the case of different-sex couples, as a question of “progressive” realization. 74. Since evaluating whether a distinction is “reasonable and objective” must be done on a case-by-case basis, the Commission, the Court, and other international courts and agencies have made use of a standard test involving several elements: (i) the existence of a legitimate goal; (ii) the suitability or logical means-to-end relationship between the goal sought and the distinction; (iii) the necessity, in order words, whether other less burdensome and equally suitable alternatives exist; and (iv) proportionality strictu sensu, i.e., the balance between the interests at stake and the level of sacrifice required from one party compared to the level of benefit of the other.57 …continuation Economic, Social and Cultural Rights, General Comment 3: The Nature of States Parties’ Obligations (paragraph 1 of Article 2 of the Covenant), December 14, 1990; UN, Committee on Economic, Social and Cultural Rights, General Comment No. 19, The right to social security (Article 9), E/C.12/GC/19, February 4, 2008, paragraphs 59, 79; I/A Court H.R. Case of Acevedo Buendía et al. ("Discharged and Retired Employees of the Comptroller”) v. Peru, Preliminary Objection, Merits, Reparations and Costs. Judgment of July 1, 2009. Series C No. 198, par. 105. 55 IACHR, Guidelines for preparation of progress indicators in the area of economic, social and cultural rights, OEA/Ser.L/V/II.132, Doc. 14 rev. 1, 19 July 2008, par. 48. 56 See, inter alia, IACHR, The Work, Education and Resources of Women: the Road to Equality in Guaranteeing Economic, Social and Cultural Rights, OEA/Ser.L/V/II.143, Doc. 59, November 3, 2011, par. 49, citing UN, Committee on Economic, Social and Cultural Rights, General Comment 3: The Nature of States Parties’ Obligations (paragraph 1 of Article 2 of the Covenant), December 14, 1990; UN, Committee on Economic, Social and Cultural Rights, General Comment No. 19, The right to social security (Article 9), E/C.12/GC/19, February 4, 2008. 57 IACHR, Application before the Inter-American Court of Human Rights, Karen Atala and Daughters, September 17, 2010, par. 86.