If you experience any technical difficulties with this video or would like to make an accessibility-related request, please send a message to [email protected]. As part of his course Price Theory and Market Design, E. Glen Weyl, Assistant Professor in Economics and the College, presents a lecture on pessimistic social choice, optimistic social choice, and the problems of voting. This course aims to show how the classical tools of price theory in the Marshallian tradition can be used to aid the design of efficient market structures and social institutions.