This paper proposes a theory of endogenous differences in liquidity of assets based on the interaction between differences in their risk and differences in liquidity needs of agents. An equilibrium of the model displays a class structure, where agents sort themselves across different types of assets according to their types. High-liquidity-need agents hold on to safer portfolios than lower-liquidity-need agents whenever the variation in the value of liquidity across states raises the value of safe assets more than that of riskier assets, and vice versa. I also derive capital asset pricing model–like formulas for excess returns where the risk and liquidity premia are interdependent and specific to each type of agent.

This paper endogenizes the market structure of an economy with heterogeneous agents who want to form bilateral matches in the presence of search frictions and when utility is nontransferable. There exist infinitely many marketplaces, and each agent chooses which marketplace to be in: agents get to choose not only whom to match with but also whom they meet with. Perfect segmentation is obtained in equilibrium, where agents match with the first person they meet. All equilibria have the same matching pattern. Although perfect assortative matching is not obtained in equilibrium, the degree of assortativeness is greater than in standard models.