Humans make hundreds of routine decisions daily. More often than not, the impact of our decisions depends on the decisions of others. As AI progresses, we are offloading more and more of these decisions to artificial agents. This research is aimed at building AI agents that make effective decisions in multiagent—part human, part artificial—environments. Current efforts are relevant to economic domains, mostly in the service of perfecting market designs. This talk will cover AI agent design in applications ranging from renewable energy markets and online ad exchanges to wireless spectrum auctions.