The effects of teamwork in time-inconsistent planning

Wednesday, February 27, 2019

12.00 p.m.

ISI seminar room 1st floor

Prof. Aristides Gionis - Aalto University, Helsinki


The problem of inconsistent planning in decision making, which leads to undesirable effects such as procrastination, has been studied in the behavioral-economics literature, and more recently in the context of computational behavioral models. Individuals, however, do not function in isolation, and successful projects most often rely on team work. Team performance does not depend only on the skills of the individual team members, but also on other collective factors, such as team spirit and cohesion. It is not an uncommon situation that a hard-working individual has the capacity to give a good example to her team-mates and motivate them to work harder.

In this work we adopt the model of Kleinberg and Oren (EC'14) on time-inconsistent planning, and extend it to account for the influence of procrastination within the members of a team. Our first contribution is to model collaborative work so that the relative progress of the team members, with respect to their respective subtasks, motivates (or discourages) them to work harder. We compare the total cost of completing a team project when the team members communicate with each other about their progress, with the corresponding cost when they work in isolation. Our main result is a tight bound on the ratio of these two costs, under mild assumptions. We also show that communication can either increase or decrease the total cost.

We also consider the problem of assigning subtasks to team members, with the objective of minimizing the negative effects of teamwork. We show that while a simple problem of forming teams of two members can be solved in polynomial time, the problem of assigning n tasks to n agents is NP-hard.

This is joint work with Aris Anagnostopoulos and Nikos Parotsidis.


Aristides Gionis is a professor in the department of Computer Science in Aalto University. He is currently a fellow in the ISI foundation, Turin, and he has been a visiting professor in the University of Rome. Previously he has been a senior research scientist and group leader in Yahoo! Research, Barcelona. He obtained his PhD in 2003 from Stanford University, USA. He is currently serving as an action editor in the Data Management and Knowledge Discovery journal (DMKD), an associate editor in the ACM Transactions on Knowledge Discovery from Data (TKDD), and an associate editor in the ACM Transactions on the Web (TWEB). He has contributed in several areas of data science, such as algorithmic data analysis, web mining, social-media analysis, data clustering, and privacy-preserving data mining. His current research is funded by the Academy of Finland (projects Nestor, Agra, AIDA) and the European Commission (project SoBigData).