This volume contains 11 thoroughly refereed and revised papers detailing recent advances in research on designing trading agents and mechanisms for agent-mediated e-commerce. They were originally presented at the Joint Workshop on Trading Agent Design and Analysis (TADA 2012) and Agent-Mediated Electronic Commerce (AMEC 2012) co-located with AAMAS 2012 in Valencia, Spain, in June 2012.

The increasing reliance on software agents has created a range of pressing new research challenges, including the design of appropriate agent decision algorithms, approaches for predicting the complex behaviors and interactions of multiple agents, including the computation of equilibria, and the engineering of protocols and mechanisms that ensure electronic markets behave in a stable manner or fulfill other desirable criteria. Drawing upon a diverse range of scientific disciplines, including computer science, economics, artificial intelligence, operations research and game theory, the papers collected in this volume represent a cross-section of recent research and cover topics such as strategies for individual trading agents, the design of markets and interaction protocols between agents, and a variety of applications.