Wealth mobility is rare in the United States, but when it occurs, mobility can offer important insight into the factors that contribute to social and economic inequalities. Wealth, or net worth, is total household assets less total debts; wealth mobility refers to change in the wealth position of an individual or group over time. The benefits of owning even a small amount of wealth can be enormous: It can provide a buffer against financial emergencies; improve education, political influence, and social connections; create more wealth when interest and dividends are reinvested; fund expenses in retirement; and be transferred to future generations. At high levels, wealth can produce enough income to make paid employment unnecessary, but even a small amount of savings or home equity can drastically improve financial security (Keister 2011a; Wolff 2010). Because wealth inequality is extreme in the United States, these benefits are not enjoyed uniformly (Keister 2000, 2005; Wolff 2004). In recent years, the top 1% of households have consistently owned about 33% of net worth, whereas 16–17% of households have had zero or negative net worth (Bucks et al. 2009; Wolff 2010). Wealth mobility is unusual because a small number of high-wealth parents can transfer both their assets and their other socioeconomic traits (e.g., education or occupation) to their children, creating considerable stability at the top end of the wealth distribution and making it difficult for those at lower levels to move up. However, both inter- and intragenerational mobility occur often enough for researchers to study them and to provide clues about the behaviors and processes that facilitate change in socioeconomic status (SES) (Keister 2005, 2007).