SinaWeibo is a Twitter-like social network service emerging in China recently. We analyzed the hot weibos (tweets), which exceed threshold of being reposted for 1000 times, from a data set of 650 million weibos during August 2009 and January 2012. We classified the hot weibos into eight...

The spread and resonance of users’ opinions on Sina Weibo, the most popular micro-blogging website in China, are tremendously influential, having significantly affected the processes of many real-world hot social events. We select 21 hot events that were widely discussed on Sina Weibo in 2011,...

The 8-th problem raised by [Hart, S., Mas-Colell, A., 2010. Bargaining and cooperation in strategic form games. Journal of the European Economics Association 8 (1), 7–33], is solved. To be specific, I show that the set of SP equilibria can be determined by a finite number of systems of linear...

The Hart-and-Mas-Colell bargaining model (Hart and Mas-Colell in J Eur Econ Assoc 8:7–33, <CitationRef CitationID="CR8">2010</CitationRef>), which is based on strategic form games, is a very promising model possessing many beautiful features. Nevertheless, it is not flawless: threats used in this model may behave quite...</citationref>

An extension of Condorcet's paradox by McGarvey (1953) asserts that for every asymmetric relation R on a finite set of candidates there is a strict-preferences voter profile that has the relation R as its strict simple majority relation. We prove that McGarvey's theorem can be extended to...

We consider a multi-period auction with a seller who has a single object for sale, a large population of potential buyers, and a mediator of the trade. The seller and every buyer have independent private values of the object. The mediator designs an auction mechanism which maximizes her revenue...

We consider a sequential rule, where an item is chosen into the group, such as a university faculty member, only if his score is better than the average score of those already belonging to the group. We study four variables: The average score of the members of the group after k items have been...

Let X_n,…,X₁ be i.i.d. random variables with distribution function F and finite expectation. A statistician, knowing F, observes the X values sequentially and is given two chances to choose X's using stopping rules. The statistician's goal is to select a value of X as large as possible. Let V_n²...