The increasing gap between those at the top and those at the bottom of the wealth distribution in Western market economies is a worrying development as it hampers equality of opportunity and distorts democratic representation. This dissertation improves our understanding of both the causes and consequences of increasing inequality by making a number of theoretical and empirical contributions. Theoretically, this dissertation provides new insights into the political foundations of wealth inequality by explaining the political economy roots of unbanked America, and by highlighting how welfare policies play a crucial role in determining whether households invest in the types of assets that build long-term wealth. Concerning the consequences of increasing inequality, this dissertation further shows how political donations and lobbying work conjointly to allow moneyed interests to shape U.S. politics. Empirically, I demonstrate that popular access to banking in the U.S. started diverging from the rest of the Western world already in the 19th century, much earlier than assumed by most scholars; I use large confidential micro-data on millions of Europeans to construct granular household-level measures of economic risk and social protection, which go far beyond the country-level measures standard in most of the literature; with my two co-authors, I further provide the first data set on moneyed interests in U.S. politics that covers the universe of lobbying reports and campaign finance filings from 1999. Taken together, my dissertation not only contributes to theoretical knowledge in political science and political economy and offers new empirical evidence on inequality but hopefully also provides those who seek a world less unequal and more financially inclusive with insights into how to get there.Ph.D.