Final answer:
The recent trend in U.S. household formation includes an increase in diverse family structures such as unmarried couples, single-parent and single-adult households, same-sex couples, and expanded households with extended family members, which also correlates with growing income inequality.
Step-by-step explanation:
A prominent recent trend in U.S. household formation is the diversification of family structures. Compared to past decades, where the typical family consisted of married parents and their unmarried children, there is now a growth in diverse household types. These include unmarried couples, single-parent households, same-sex couples, single-adult households, as well as expanded households with extended family members like grandparents, cousins, or adult children living together. This diversity in family makeup has also corresponded with a rise in income inequality, as the changing structures often reflect the varying economic statuses of households, from single-parent families at the lower end of the income distribution to high-earning dual-career couples at the upper end.
Additionally, the notions of marriage and family are evolving, as more single individuals and cohabitating couples choose to raise children through surrogacy or adoption, challenging the traditional view of nuclear families.