An orphanage is a residential institution, total institution or group home, devoted to the care of orphans and children who, for various reasons, cannot be cared for by their biological families. The parents may be deceased, absent, or abusive. There may be substance abuse or mental illness in the biological home, or the parent may simply be unwilling to care for the child. The legal responsibility for the support of abandoned children differs from country to country, and within countries. Government-run orphanages have been phased out in most developed countries during the latter half of the 20th century but continue to operate in many other regions internationally. It is now generally accepted that orphanages are detrimental to the emotional wellbeing of children, and government support goes instead towards supporting the family unit.