To create a truly sustainable world, we need to generate
ample resources and allocate them appropriately. In traditional
economics, these goals are achieved using money. However, in many
settings of particular social significance, monetary transactions are
infeasible, be it due to ethical considerations or technological
constraints. In this talk, we will discuss alternatives to money,
including risk, social status, and scarcity, and show how to use them to
achieve socially-optimal outcomes. Risk helps determine a person's
value for a resource: the more someone is willing to risk for something,
the more they value it. Using this insight, we propose an algorithm to
find a good assignment of students in school choice programs. Social
status helps motivate people to contribute to a public project. Using
this insight, we design badges to maximize contributions to
user-generated content websites. Scarcity forces people to evaluate
trade-offs, allowing algorithms to infer the relative strength of their
preference for different options. Using this insight, we design voting
schemes that select the most highly-valued alternative.