  As the driving force of crowdsourcing is the interaction among participants,
various incentive mechanisms have been proposed to attract sufficient
participants. However, the existing works assume that all the providers always
meet the deadline and the task value accordingly remains constant. To bridge
the gap of such impractical assumption, we model the heterogeneous punctuality
behavior of providers and the task value depreciation of requesters. Based on
those models, we propose an Expected Social Welfare Maximizing (ESWM) mechanism
that aims to maximize the expected social welfare in polynomial time.
Simulation results show that our heuristic-based mechanism achieves higher
expected social welfare and platform utility via attracting more participants.
