Though there is quite a lot of papers which focus on different areas of AGT, the following three seems very interesting to me as they are trying to catch up either a new area or exploring a classical but important area.

*Krzysztof Apt and Evangelos Markakis*. **Diffusion in Social Networks with Competing Products**

**Abstract: ** We introduce a new threshold model of social networks, in which the nodes influenced by their neighbours can adopt one out of several alternatives. We identify a class of graphs that allow us to characterize social networks for which adoption of a product by the whole network is possible (respectively necessary) and the ones for which a unique outcome is guaranteed. We also provide a simple polynomial time algorithm that allows us to determine whether a graph belongs to this class. This directly yields polynomial time algorithms that allows us to determine whether a given social network satisfies one of the above properties. We also study algorithmic questions concerning networks without unique outcomes. In particular we show that the problem of computing the minimum possible spread of a product is NP-hard to approximate with an approximation ratio better than $\Omega(n)$, in contrast to the maximum spread, which is efficiently computable. We then move on to questions regarding the behavior of a node with respect to adopting some (resp. a given) product. We show that the problem of determining whether a given node has to adopt some (resp.~a given) product in all final networks is co-NP-complete.

*Asaph Arnon and Yishay Mansour*. **Repeated Budgeted Second Price Ad Auction**

** Abstract: ** Our main goal is to abstract existing repeated sponsored search ad auction mechanisms which includes budgets, and study their equilibrium and dynamics. Our abstraction has multiple agents biding repeatedly for multiple identical items (such as impressions in an ad auction). The agents are budget limited and have a value for per item. We abstract the repeated interaction as a one-shot game, which we call “budget auction”, where agents submit a bid and a budget, and then items are sold by a sequential second price auction. Once an agent exhausts its budget it does not participate in the proceeding auctions. Our main result is that if agents bid conservatively (never bid above their value) then there always exists a pure Nash equilibrium. We also study simple dynamics of repeated budget auctions, showing their convergence to a Nash equilibrium for two agents and for multiple agents with identical budgets.

# Some very interesting papers in SAGT 2011

*Navendu Jain, Ishai Menache, Joseph Naor and Jonathan Yaniv*.

**A Truthful Mechanism for Value-Based Scheduling in Cloud Computing**

**Abstract:**Cloud computing provides an attractive computation platform, in which computing resources (e.g., virtual machines, storage capacity) are rented to end-users under a utility pricing model. The most common pricing offering is a pay-as-you-go scheme, in which users are charged a fixed price per unit resource per hour. While this scheme is simple to implement, it does not support value-based scheduling, where users assign a value to their job and the cloud schedules to maximize aggregate value (or prioritize competing jobs) under job demand and capacity constraints. In this paper, we introduce a novel pricing approach for batch jobs (e.g., image processing, financial analytics, scientific simulations). In our economic model, users submit jobs with a value function that specifies willingness to pay as function of job due dates. Focusing on social-welfare as the system objective (especially relevant for private or in-house clouds), we construct a resource allocation algorithm which obtains a (small) constant-factor approximation of maximum aggregate value, assuming that user valuations are known. Based on this algorithm, we then design an efficient truthful-in-expectation mechanism, which significantly improves the running complexity of black-box reduction mechanisms that can be applied to the problem, thereby facilitating its implementation in real systems.

The complete list of accepted papers is here.

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