A/HRC/45/39 15. The main challenges and obstacles that some States face in their approach are a lack of funding, efficient development projects and sufficiently qualified personnel. Such challenges can be mitigated by mobilizing internal efforts and by intensifying international cooperation aimed at promoting development projects in recipient countries. 16. Developments to date show the importance of the engagement of OHCHR, United Nations regional bodies and other international organizations in mobilizing State authorities, at the central and local levels, civil society elements and the private sector, to adopt programmes, plans and other measures aimed at implementing the Sustainable Development Goals. III. Leaving no one behind 17. The crucial and cross-cutting principle of the Sustainable Development Goals is leaving no one behind. All efforts are required to ensure equality of treatment and of opportunities, to eliminate discrimination and to ensure equal rights for all, in particular those belonging to vulnerable groups, such as women, children and young people, indigenous peoples, persons with disabilities, older persons, migrants and asylum seekers, without distinction of any kind on the basis of race, colour, descent, sex, sexual orientation, language, religion, political or other opinion, ethnic, national or social origin, property, birth, disability or other status, and beginning with those who are the furthest behind, 2 mindful that a person can be vulnerable on several of those grounds. 18. Vulnerable groups, the furthest behind and the status of realization of the Sustainable Development Goals varies between countries. That makes it necessary for the authorities of each State to identify vulnerable groups, communities and individuals and those at risk of being left behind in their territories. That assessment is key to reaching the Goals, but it is not available everywhere, and some communities are still neglected. 3 In order to adopt adequate policies and measures, reliable statistics and data are necessary in order to make a baseline assessment and to evaluate the results of the measures taken. States should ensure that data collection is not biased, does not create or reinforce discrimination or stereotypes and is developed with the meaningful participation of those concerned and other stakeholders, while fully respecting the right to privacy. Moreover, data must be disaggregated on the basis of gender, ethnic origin, age and other appropriate criteria, in order to reveal the disparities and specific challenges faced by different population groups. States and stakeholders should also develop online tools to allow access to information, facilitate reporting, evaluate progress and ensure the coordination of measures taken to fulfil different goals. Forty-seven per cent of the countries of the world lack the information needed for assessing the status of implementation of the Goals. OHCHR and other United Nations bodies should continue to assist States to develop and use appropriate indicators and statistics for measuring progress. As a good practice, in Kenya, State bodies and the National Commission on Human Rights have worked to identify groups that may be at risk of being left behind and established a preliminary list of 25 such population groups. 19. National policies, plans and programmes should give practical contents to the commitment to leave no one behind, focusing on the furthest behind and advancing specific measures, bearing in mind that that commitment will only be achieved through the implementation of all Sustainable Development Goals for all groups and individuals. Such national policies must be adopted with the widest participation of local government, representatives of those concerned and other stakeholders, including the private sector. 2 3 6 Economists, including a Nobel Prize laureate, propose to analyse vulnerability as a capability approach, in terms of individual well-being, the assessment of the social organization and the possibilities for a drastic change in society (see the work of Amartya Sen and Martha Nussbaum). In the Human Development Report 2019, the United Nations Development Programme (UNDP) sets out the concept of the need to move from basic to enhanced capabilities in order to respond to the new inequalities in human development. Economic and Social Council, press release No. 6939 of 13 July 2018.