One of the most striking changes in American society in the last forty years has been the decline and delay in marriage. The fraction of young men and women who have never been married increased significantly between 1970 and 2000. Idiosyncratic labor income volatility also increased over the same period. This first chapter of this dissertation establishes a quantitatively important link between these two facts. Specifically, if marriage involves consumption commitments, then a rise in income volatility results in a delay in marriage. Marriage, however, also allows for diversification of income risk since earnings fluctuations between spouses need not be perfectly correlated. The hypothesis that rising income volatility contributed to the d...