Market design is a field of economics that focuses on creating and improving markets to enhance their efficiency and fairness. It involves understanding how different market structures work and how to best match supply and demand. Market designers often use mathematical models and experiments to test their ideas and find solutions to real-world problems. One key aspect of market design is the allocation of resources, such as in auction systems or matching markets. For example, the design of school choice programs helps match students to schools based on preferences, ensuring that both students and schools benefit from the arrangement.