ANNEX I. >> Metadata sheets on selected indicators certain extent the degree to which the State has maintained affordable housing and, thus, made housing accessible. It is an outcome indicator related to the “housing affordability” attribute of the right to adequate housing. Method of computation  The indicator is computed as the total number of homeless persons to the total population multiplied by 100,000. Data collection and source  The main source of data for this indicator is administrative records of the State (registers) and homeless services (e.g., transitional shelters, health and social security agencies). Data can also be gathered from population censuses and household surveys at the national and subnational levels. Periodicity  In general, data from administrative records are available annually. Population censuses are often conducted every five to ten years, while household surveys are usually conducted every three to five years. Disaggregation  The indicator should be disaggregated by sex, age, economic and social situation, ethnicity, minority, indigenous, colour, language, religion, political or other opinion, national or social origin, migrant, disability, sexual orientation, marital and family status. In addition, disaggregation of the indicator by place of residence (region and rural/urban) is useful in assessing disparities in access to housing. Comments and limitations  Homelessness is often a root cause and an effect of complex social and economic problems. Homelessness can be caused by diverse and multifaceted factors, including a lack of affordable housing, speculation in housing and land for investment purposes, privatization of civic services, ethnic and armed conflict, and rapid ill-planned urbanization. It is also linked to landlessness in some settings, and there is a growing tendency to criminalize the homeless and increasing violence towards them (see E/CN.4/2005/48).  The Committee on Economic, Social, and Cultural Rights, in its general comment No. 4 (1991), specifies that States have the obligation to effectively monitor the situation with respect to housing, “‘provide detailed information about those groups within [...] society that are vulnerable and disadvantaged with regard to housing.’ They include, in particular, homeless persons and families, those inadequately housed and without ready access to basic amenities, those living in ‘illegal’ settlements, those subject to forced evictions and low-income groups”. The lack of secure tenure and forced evictions are conditions that could lead to homelessness. The Committee’s general comment No. 7 (1997) provides that “evictions should not result in individuals being rendered homeless or vulnerable to the violation of other human rights”. There are several definitions of homelessness, ranging from a narrow one that covers only rooflessness and houselessness to a broader one that classifies persons who are homeless according to their living or “home” situation. The Special Rapporteur to adequate housing recommends a broader definition of homelessness, since a narrow definition is inadequate and does not recognize that an element of social exclusion is part of the experience of the homeless (see E/CN.4/2005/48).  The Australian Bureau of Statistics identifies three categories of homelessness: “primary” homelessness refers to people without conventional accommodation; “secondary” homelessness refers to those moving frequently from one form of temporary shelter to another; and “tertiary” homelessness refers to people who live medium to long term in boarding houses. An additional category is constituted by people in housing situations close to the minimum standards (e.g., in caravans) (A/HRC/4/18/Add.2). Human Rights Indicators 165