among the most urgent concerns of older persons worldwide is income security. this poses challenges for governments with aging populations to ensure investments in pension systems continues in order to provide economic independence and reduce poverty in old age. these challenges vary for developing and developed countries. unfpa stated that, "sustainability of these systems is of particular concern, particularly in developed countries, while social protection and old-age pension coverage remain a challenge for developing countries, where a large proportion of the labour force is found in the informal sector."