The dissertation consists of three essays on industrial organization with a particular focus on the structures of financial markets. The first chapter theoretically studies how search friction affects competition and resource allocation in crowdfunding loan markets, which are described using a many-to-one matching framework. Namely, competitive fundraisers must accumulate multiple investors to complete a transaction. I develop a dynamic matching model with a fixed sample search, a la Burdett and Judd (1983), in which fundraisers compete in interest rates while investors look for good investment targets. I highlight two important economic forces in the model. First, investors can only observe a limited number of quotes. Second, a surplus cannot be created until a fundraiser attracts contributions from enough investors. I show that in the presence of search friction, fundraisers implement mixed strategies to set interest rates in a unique stationary equilibrium, which results in rate dispersion even if the goods are homogeneous. Regarding resource allocation, I show that in the many-to-one market, rate dispersion creates an endogenous coordination mechanism among anonymous and independent investors, thereby making it easy for them to concentrate their investments. In other words, search friction improves allocation efficiency in a crowdfunding market compared with its perfect competition counterpart. Based on the theoretical framework constructed in the first chapter, the second chapter empirically studies the market structure of the crowdfunding market. I construct a novel data set based on a large panel of fundraisers' behaviors. Using reduced form analysis, I find evidence of persistent rate dispersion and funding mismatches, which are consistent with the theoretical predictions of the search model. I also show that the model is identifiable and can be estimated using a non-parametric approach, which allows me to measure the allocation efficiency. Regarding methodology, I demonstrate that it is sufficient to use projects' ranks to recover search friction primitives, which reduces the computational burden and increases the precision. The third chapter studies how the combination of adverse selection and moral hazard affects the design of financial contracts. Specifically, the chapter studies an optimal mechanism design problem,a la Mussa and Rosen (1978), in the presence of limited enforcement. In the study, the bank (principal) designs loan contracts to screen firms (agents) with unobserved productivities. Meanwhile, the bank cannot prevent the firm from consuming acquired funds without producing anything. The impediment of forming contracts creates an endogenous outside option for all borrowers. I show that in the optimal mechanism, loan sizes for higher types are decreased by ironing, i.e., by pooling on the top. In addition, the lower types produce at the second-best level. Moreover, I show that firms' participation is independent of the enforcement level.