An absolute poverty line refers to a set standard of what households should be able to have in order to meet their basic (mostly food) needs. A relative poverty line is defined in relation to the overall distribution of income or consumption in a country. For example, the main poverty line used in the Organization for Economic Cooperation and Development (OECD) and the European Union is a relative poverty measure based on “economic distance,” a level of income usually set at 50 or 60 per cent of the median household income. However, as a result of the HIV/AIDS pandemic, conflicts, shocks such as recurrent droughts and rapid urbanization, many older persons in sub-Saharan Africa have become primary sources of support for their families and/or caregivers for grandchildren because prime-age adults have fallen ill, died or migrated.