This dissertation comprises three self-contained chapters, in which I investigate the effect of demographic changes and policies on intra household allocations when the relative bargaining power is endogenously determined. In Chapter 2, I use a quantitative model to evaluate the effect of imbalanced sex ratios on female and male welfare in China. The imbalanced sex ratio affects the marriage market, which changes the relative bargaining power within the household, and hence individual labor supply and welfare. Chapter 3 further investigates the imbalanced sex ratio problem in China empirically and provides evidence in support of the arguments in Chapter 2. Chapter 4 studies the effect of a counter-factual income tax reform from joint taxati...