expectancy has increased while fertility rates have decreased. This means that more children are growing up while their grandparents are still alive and able to become involved in childcare. In addition, the reduced fertility rates mean that grandparents can devote more attention and resources to their only grandchildren. Second, more mothers are involved in the workforce, and thus, other caregivers need to be present to care for the child. For instance, in Hong Kong, 55% of grandparents reported that they took care of their grandchild because his or her parents have to work. In South Korea, 53% of working mother reported that they once received child care services from their parents. Third, the increasing number of single-parent families creates a need for grandparental support. The degree of grandparent involvement also varies depending on the societal context, such as the social welfare policies. For example, in European countries such as Sweden and Denmark, where formal childcare is widely available, grandparents provide less intensive childcare. By contrast, in European countries such as Spain and Italy, where formal childcare is limited, and welfare payment is low, grandparents provide more intensive childcare. In Singapore, the grandparent caregiver tax relief was established in 2004, which enables working parents (Singapore citizens with children age 12 and below) whose children are being cared for by unemployed grandparents to receive income tax relief of 3,000 Singaporean dollars. Types There are different types of grandparental involvement, including nonresident grandparents, co-resident grandparents, grandparent-maintained household, and custodial grandparents. Nonresident grandparents: Grandparents who do not live with their grandchildren, but provide care for them, such as picking them up from school. Co-resident grandparents: Grandparents who live with their grandchild, as well as their parents. This type of household is also known as three-generational households. According to a report that uses data from the 2010 Census, the American Community Survey (ACS), the Current Population Survey (CPS), and the Survey of Income and Program Participation (SIPP), co-resident grandparents are more likely to be in poverty and suffer from an illness or disability. Grandparent-maintained households: A grandparent who is in charge of the household. In this type of household, the parents may or may not be present. In the US, 33% of children who live in a grandparent-maintained household have only the grandparents present; this is comparable to another 30% who live with a grandmother and one or more parents. Custodial grandparents: Grandparents who raise