E Wah, M Wright, and MP Wellman

Journal of Artificial Intelligence Research 59:613–650, 2017.

Revised and significantly extended version of a paper presented at:

International Conference on Autonomous Agents and Multiagent Systems, May 2015.
** Winner: Pragnesh Jay Modi Best Student Paper Award (for Elaine Wah)


We investigate the effects of market making on market performance, focusing on allocative efficiency as well as gains from trade accrued by background traders. We employ empirical simulation-based methods to evaluate heuristic strategies for market makers as well as background investors in a variety of complex trading environments. Our market model incorporates private and common valuation elements, with dynamic fundamental value and asymmetric information. In this context, we compare the surplus achieved by background traders in strategic equilibrium, with and without a market maker. Our findings indicate that the presence of the market maker strongly tends to increase total welfare across various environments. Market-maker profit may or may not exceed the welfare gain, thus the effect on background-investor surplus is ambiguous. We find that market making tends to benefit investors in relatively thin markets, and situations where background traders are impatient, due to limited trading opportunities. The presence of additional market makers increases these benefits, as competition drives the market makers to provide liquidity at lower price spreads. A thorough sensitivity analysis indicates that these results are robust to reasonable changes in model parameters.
A preliminary version (obsolete) was presented at the AAMAS-14 Workshop on Agent-Mediated Electronic Commerce and Trading Agent Design and Analysis (AMEC/TADA).