The Phenomenon. Lone- or single-parent families, primarily lone mothers are becoming an increasingly significant family type in all the advanced industrialized countries (see Table 2.17a).According to Eurostat, lone parents are those who live alone with their dependent children (Lehmann and Wirtz, 2004). Dependent children are those under age 16 or 16-24 and living in a household of which at least one of their parents is a member and who are economically inactive (e.g. in education or training). Cohabiting couples, another growing family type, are no longer counted as single parents, at least in most countries.