We distinguish among three types of symmetric games, which we name ordinary symmetric games, renaming symmetric games, and name-irrelevant symmetric games, in an order of increasing broadness. The second class of symmetric games is new and has bite even on some elementary two by two games, e.g.,...

We study the Stackleberg variant of the repeated Sequential Prisoner’s Dilemma (SPD for short). The game goes in two stages, and the two players, the leader and the follower, are asymmetric in both stages. In the first stage of the game, the leader chooses a strategy (for the repeated SPD of...

There are two recognized classes of strategic-form symmetric games, both of which can be conveniently defined through the corresponding player symmetry groups. We investigate the basic properties of these groups and several related concepts. We generalize the notion of coveringness of...

The minimum-cost-spanning-tree (m.c.s.t.) game is a classical cooperative game model that has been extensively studied. We consider the problem of decreasing the connection costs as much as possible in an m.c.s.t. game such that its core does not change. We define the desired m.c.s.t. game as...

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 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...

Statistical models in econometrics, biology, and most other areas, are not expected to be correct, and often are not very accurate. The choice of a model for the analysis of data depends on the purpose of the analysis, the relation between the data and the model, and also on the sample or data...