Elderly households, those headed by young people, lone-parent families, fragmented families and large families are particularly at risk of being poor in many OECD member countries. Predicted trends in family structure suggest that the future will see further growth in these types of families: projected trends suggest that declining marriage rates, rising divorce rates and increased cohabitation are likely to continue while the number of births outside marriage and the preponderance of children living in step- or single-parent households appear likely to rise. Longevity will also continue to increase.